I've got JDK 14 installed, and I can't install NetBeans plugins. After looking carefully at what exactly happened, it seems like NetBeans plugins are installed using the Pack200 API, which was removed in JDK 14. I don't think Apache is aware of this old NetBeans way of installing NetBeans plugins, so is there a workaround to this? I'm using Apache NetBeans 12.0, if that helps. Thanks!
This problem has been discussed on the mailing list.
There's also a Jira ticket for it that mentions a few work-arounds. One of them: use an old JDK for installing the plugin (and switch back to JDK 14 after that) or as an alternative copy /jdk-13/bin/pack200 to /jdk-14/bin (or set a symbolic link).