Error: `parentNode` property of given node is `undefined`

[IanStorm]

Just for some hours now, our gulp build process stopped working due to an error in gulp-javascript-obfuscator:

C:\...\node_modules\gulp-javascript-obfuscator\
node_modules\javascript-obfuscator\dist\webpack:\JavaScriptObfuscator\src\node\N
odeUtils.ts:237
            throw new ReferenceError('`parentNode`property of given node is `un
defined`');
                  ^
ReferenceError: `parentNode` property of given node is `undefined`

(Note that I have "..." the path to the actual folder.)

After quickly digging into the problem, I have found that javascript-obfuscator has release v0.17.0 just today (some hours) ago. If I manually downgrade inside the gulp-javascript-obfuscator the javascript-obfuscator to 0.16.0 (instead of latest) it works again. I know this cannot be the actual solution, but it could be a starting point however.

Any suggestions?
Thanks in advance.
Please, if more information is required from my side, tell me.