Exception during WebFlux tests: NoClassDefFoundError: KotlinModule$Builder

[programista-zacny]

Case

• SpringBoot 3.0.4 WebFlux
• Springdoc 2.0.3
• Temurin JDK17

Normally starting application cause NO errors at all. Everything is running smooth and well.

During tests (build or manually triggered tests) I'm getting exception:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springdoc.core.configuration.SpringDocKotlinConfiguration': Failed to instantiate [org.springdoc.core.configuration.SpringDocKotlinConfiguration]: Constructor threw exception
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:324) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:312) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1344) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1188) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:561) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:521) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:326) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:324) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:200) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:961) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:917) ~[spring-context-6.0.6.jar:6.0.6]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:584) ~[spring-context-6.0.6.jar:6.0.6]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:732) ~[spring-boot-3.0.4.jar:3.0.4]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:434) ~[spring-boot-3.0.4.jar:3.0.4]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:310) ~[spring-boot-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.context.SpringBootContextLoader.lambda$loadContext$3(SpringBootContextLoader.java:137) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:59) ~[spring-core-6.0.6.jar:6.0.6]
	at org.springframework.util.function.ThrowingSupplier.get(ThrowingSupplier.java:47) ~[spring-core-6.0.6.jar:6.0.6]
	at org.springframework.boot.SpringApplication.withHook(SpringApplication.java:1388) ~[spring-boot-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.context.SpringBootContextLoader$ContextLoaderHook.run(SpringBootContextLoader.java:545) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:137) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:108) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:184) ~[spring-test-6.0.6.jar:6.0.6]
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:118) ~[spring-test-6.0.6.jar:6.0.6]
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:127) ~[spring-test-6.0.6.jar:6.0.6]
	at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.postProcessFields(MockitoTestExecutionListener.java:110) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.injectFields(MockitoTestExecutionListener.java:94) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener.prepareTestInstance(MockitoTestExecutionListener.java:61) ~[spring-boot-test-3.0.4.jar:3.0.4]
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:241) ~[spring-test-6.0.6.jar:6.0.6]
	at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:138) ~[spring-test-6.0.6.jar:6.0.6]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$10(ClassBasedTestDescriptor.java:377) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.executeAndMaskThrowable(ClassBasedTestDescriptor.java:382) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$11(ClassBasedTestDescriptor.java:377) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[na:na]
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:310) ~[na:na]
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:735) ~[na:na]
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734) ~[na:na]
	at java.base/java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:734) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) ~[na:na]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.invokeTestInstancePostProcessors(ClassBasedTestDescriptor.java:376) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$instantiateAndPostProcessTestInstance$6(ClassBasedTestDescriptor.java:289) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.instantiateAndPostProcessTestInstance(ClassBasedTestDescriptor.java:288) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$4(ClassBasedTestDescriptor.java:278) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at java.base/java.util.Optional.orElseGet(Optional.java:364) ~[na:na]
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$5(ClassBasedTestDescriptor.java:277) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.execution.TestInstancesProvider.getTestInstances(TestInstancesProvider.java:31) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$prepare$0(TestMethodTestDescriptor.java:105) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:104) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:68) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$prepare$2(NodeTestTask.java:123) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.prepare(NodeTestTask.java:123) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:90) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask$DefaultDynamicTestExecutor.execute(NodeTestTask.java:226) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask$DefaultDynamicTestExecutor.execute(NodeTestTask.java:204) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:142) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.lambda$execute$2(TestTemplateTestDescriptor.java:110) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:183) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:992) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:762) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:992) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline$7$1.accept(ReferencePipeline.java:276) ~[na:na]
	at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1625) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:150) ~[na:na]
	at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:173) ~[na:na]
	at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234) ~[na:na]
	at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596) ~[na:na]
	at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:110) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.jupiter.engine.descriptor.TestTemplateTestDescriptor.execute(TestTemplateTestDescriptor.java:44) ~[junit-jupiter-engine-5.9.2.jar:5.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:151) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511) ~[na:na]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:41) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$6(NodeTestTask.java:155) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:141) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$9(NodeTestTask.java:139) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:138) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:95) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:35) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:54) ~[junit-platform-engine-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:147) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:127) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:90) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:55) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:102) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:54) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:114) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:86) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.DefaultLauncherSession$DelegatingLauncher.execute(DefaultLauncherSession.java:86) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at org.junit.platform.launcher.core.SessionPerRequestLauncher.execute(SessionPerRequestLauncher.java:53) ~[junit-platform-launcher-1.9.2.jar:1.9.2]
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:57) ~[junit5-rt.jar:na]
	at com.intellij.rt.junit.IdeaTestRunner$Repeater$1.execute(IdeaTestRunner.java:38) ~[junit-rt.jar:na]
	at com.intellij.rt.execution.junit.TestsRepeater.repeat(TestsRepeater.java:11) ~[idea_rt.jar:na]
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:35) ~[junit-rt.jar:na]
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:235) ~[junit-rt.jar:na]
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:54) ~[junit-rt.jar:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springdoc.core.configuration.SpringDocKotlinConfiguration]: Constructor threw exception
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:223) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:110) ~[spring-beans-6.0.6.jar:6.0.6]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:321) ~[spring-beans-6.0.6.jar:6.0.6]
	... 154 common frames omitted
Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/module/kotlin/KotlinModule$Builder
	at org.springdoc.core.configuration.SpringDocKotlinConfiguration.<init>(SpringDocKotlinConfiguration.kt:47) ~[springdoc-openapi-starter-common-2.0.3.jar:2.0.3]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
	at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) ~[na:na]
	at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
	at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[na:na]
	at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480) ~[na:na]
	at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:210) ~[spring-beans-6.0.6.jar:6.0.6]
	... 156 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.module.kotlin.KotlinModule$Builder
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[na:na]
	... 163 common frames omitted

[vnobo]

Caused by: java.lang.NoClassDefFoundError: com/fasterxml/jackson/module/kotlin/KotlinModule$Builder
at org.springdoc.core.configuration.SpringDocKotlinConfiguration.(SpringDocKotlinConfiguration.kt:47) ~[springdoc-openapi-starter-common-2.0.3.jar:2.0.3]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:77) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstanceWithCaller(Constructor.java:499) ~[na:na]
at java.base/java.lang.reflect.Constructor.newInstance(Constructor.java:480) ~[na:na]
at kotlin.reflect.jvm.internal.calls.CallerImpl$Constructor.call(CallerImpl.kt:41) ~[kotlin-reflect-1.7.22.jar:1.7.22-release-288(1.7.22)]
at kotlin.reflect.jvm.internal.KCallableImpl.call(KCallableImpl.kt:108) ~[kotlin-reflect-1.7.22.jar:1.7.22-release-288(1.7.22)]
at kotlin.reflect.jvm.internal.KCallableImpl.callDefaultMethod$kotlin_reflection(KCallableImpl.kt:159) ~[kotlin-reflect-1.7.22.jar:1.7.22-release-288(1.7.22)]
at kotlin.reflect.jvm.internal.KCallableImpl.callBy(KCallableImpl.kt:112) ~[kotlin-reflect-1.7.22.jar:1.7.22-release-288(1.7.22)]
at org.springframework.beans.BeanUtils$KotlinDelegate.instantiateClass(BeanUtils.java:896) ~[spring-beans-6.0.6.jar:6.0.6]
at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:191) ~[spring-beans-6.0.6.jar:6.0.6]
... 26 common frames omitted
Caused by: java.lang.ClassNotFoundException: com.fasterxml.jackson.module.kotlin.KotlinModule$Builder
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:520) ~[na:na]
... 38 common frames omitted

[bnasslahsen]

If you have kotlin classes in your classpath see additionnal dependency you should have:
https://springdoc.org/v2/#kotlin-support

Or you can disable kotlin detection:
springdoc.enable-kotlin=false

If you believe having Other issue, Provide a Minimal, Reproducible Example - with HelloController that reproduces the problem

[programista-zacny]

com.squareup.okhttp3:mockwebserver maybe is the cause:

[INFO] \- com.squareup.okhttp3:mockwebserver:jar:4.10.0:test
[INFO]    +- com.squareup.okhttp3:okhttp:jar:4.10.0:test
[INFO]    |  +- com.squareup.okio:okio-jvm:jar:3.0.0:test
[INFO]    |  |  \- org.jetbrains.kotlin:kotlin-stdlib-common:jar:1.7.22:test
[INFO]    |  \- org.jetbrains.kotlin:kotlin-stdlib:jar:1.7.22:test
[INFO]    |     \- org.jetbrains:annotations:jar:13.0:test
[INFO]    +- junit:junit:jar:4.13.2:test
[INFO]    |  \- org.hamcrest:hamcrest-core:jar:2.2:test
[INFO]    \- org.jetbrains.kotlin:kotlin-stdlib-jdk8:jar:1.7.22:test
[INFO]       \- org.jetbrains.kotlin:kotlin-stdlib-jdk7:jar:1.7.22:test

Edit1: Why then version 2.0.2 was working without any issue?
Edit2: Why are you closing this issue straight away? I was using version 2.0.2 without any problem. I have just upgraded to 2.0.3 and suddenly something went wrong, I didn't change anything in my code (e.g. new Kotlin dependency) except to enter the new version of Springdoc.

[programista-zacny]

@bnasslahsen Please see my latest comment ;)

[bnasslahsen]

com.squareup.okhttp3:mockwebserver maybe is the cause:

[INFO] \- com.squareup.okhttp3:mockwebserver:jar:4.10.0:test
[INFO]    +- com.squareup.okhttp3:okhttp:jar:4.10.0:test
[INFO]    |  +- com.squareup.okio:okio-jvm:jar:3.0.0:test
[INFO]    |  |  \- org.jetbrains.kotlin:kotlin-stdlib-common:jar:1.7.22:test
[INFO]    |  \- org.jetbrains.kotlin:kotlin-stdlib:jar:1.7.22:test
[INFO]    |     \- org.jetbrains:annotations:jar:13.0:test
[INFO]    +- junit:junit:jar:4.13.2:test
[INFO]    |  \- org.hamcrest:hamcrest-core:jar:2.2:test
[INFO]    \- org.jetbrains.kotlin:kotlin-stdlib-jdk8:jar:1.7.22:test
[INFO]       \- org.jetbrains.kotlin:kotlin-stdlib-jdk7:jar:1.7.22:test

Why then version 2.0.2 was working without any issue?

For this kind of questions, you should refer to the CHANGELOG: https://github.com/springdoc/springdoc-openapi/releases/tag/v2.0.3

You will find: #2006 - Support for nullable request parameters in Kotlin

It's also clearly stated in the documentation when using kotlin with springdoc-openapi v2:
Your project should add jackson-module-kotlin to the list of dependencies.

NOTE: This dependency is by default transitively included with springdoc-openapi-kotlin module in springdoc-openapi v1.

It's important to make sure you know What librairies you are loading. And what beans you need to load.

The error is enough clear to guide you resolve your project dependencies issue:
It should help you decide whether or not you want enable Kotlin SpringDoc Beans.

[bnasslahsen]

As discussed with @breun in another thread,

SpringDocKotlinConfiguration is annotated for checking Kotlin classes presence.
The project is that now in the v2 with the common module - we can not predict the intention of the project.(whether or not they want enable kotlin support)

Most of the comments are for the majority related to project dependencies misconfiguration, or people not reading the documentation for v2 and sometimes people not even knowing they were shipping kotlin classes.

We will consider the change of adding an extra @ConditionalOnClass(KotlinModule.Builder.class) but there will be a trade-off to accept here:

Even if the projects doesn't declare jackson-module-kotlin, the application will start. And there will be no notification for people who misconfigure the kotlin module, leading sometimes to wrong beans loaded and some other times to wrong results.