I went to upgrade my NW6.5 box to spack 5. The install went fine until
right at the end when it tried to shut down the jvm. The java -killall and
java -exit commands popped up on the console and then the system hung.

In the logger screen I see the message:

Module STOPX.NLM load status OK
Java: JAVA.NLM should not be unloaded because of one or more suspended classes.
Java: An exception occurred while cleaning up Help. The JVM running this
class is permanently suspended and its resources are unrecoverable.

After rebooting quite a few services crash on startup (mainly tomcat).

I tried back-revving but the uninstall never gets started as it hangs with
the same jvm errors.

Any suggestions?