Could you give me an advise regarding java issue that I am having on NetWare6.5 SP6, pls?

I am upgrading NW65SP6 to SP7 on VMWARE ESX3, and having an issue with JAVA.NLM.
Other NetWare6.5 servers are upgraded to SP7 without any problems.
Only one of them is having this issue and unable to complete sp7 upgrade.
I took snapshot when it was SP6, so the server has been running as SP6 as it was, and now I am trying to resolve this issue in order to upgrade the server to SP7.

It seems it is unable to unload JAVA.NLM during upgrade to SP7.
When I run unload java, it shows the same error message, too.

Error message:
java: Page fault processor exeption occured while executing class com.novell.application.install.NISetup

State of Registers at Processor Exception:
EIP=9CE9EE90, EFLAGS=10202, EAX=6A, EDX=68

The exception occured while executing code in: JAVA.NLM (9ce87000)
The exception occured while running thread: Java_581 Main (7B049420)

Java: An exception occured while cleaning up com.novell.application.install.NISsetup.
The JVM running this class is permanently suspended and its resources are unrecoverable.

If startx is run, GUI screen comes up but nothing can be run.
- no wall paper
- memu starts but nothing can be click