Sorry for the problem.
We just fixed a problem on our NetBeans Integration. That, some jars are missing in our NetBeans plugin.
In our testing, if starting NetBeans with Java 11 JDK specified, the missing jar will make FileNotFound exception and make NetBeans failed to start.
FYI, in my testing, Java 8 can start NetBeans; Java 11 cannot; and since Java 9 and 10 are end-of-supported, I cannot test them.
Please update the software to latest patch build (20181130am or later) to get the problem fixed. Details about update to latest patch can be found at