Description
For the serial monitor, the JSSC library is used. On linux (and possibly other OS's as well), this requires a small native library, which is automatically unpacked from the .jar file into the ~/.jssc directory. However, when this unpacking fails, not message is shown about that. Instead, an exception is thrown and logged when opening the serial monitor:
Exception in thread "AWT-EventQueue-0" java.lang.UnsatisfiedLinkError: jssc.SerialNativeInterface.openPort(Ljava/lang/String;Z)J
This can be reproduced by removing ~/.jssc and replacing it with a regular file or broken symlink. Removing permissions on the directory (which might happen when somebody runs the IDE as root) will probably also trigger it.
It would be better if the actual problem would be reported, so the user can act on that, instead of just showing the linkage error which is just a secondary symptom.
This is a followup issue for #7516, which was about the linkage error shown above (it also has a more complete backtrace).