Java in Forms6

Question

I have a problem when I try to upload java into my custom form 6.
On my windows computer everything works fine
when I move it to E-Business environment on Linux environment it compile successfully
but when I call any java procedure it raise FRM-105100.
eg on such row
     JO:=STRING_.NEW;
I have check the CLASSPATH million times, moreover during forms opening I can see my jars in bottom tray.
I have found recommendation to use this type of debugging
WHEN ORA_JAVA.JAVA_ERROR then
ex := ORA_JAVA.LAST_EXCEPTION;
message(EXCEPTION_.TO_STRING(ex));
But when I uload EXCEPTION_ class to my form the PL/SQL package I get as result has only 4 different NEW functions.
There is no TO_STRING function at all.
Do you have any ideas what it can be?

Answer 1

Correct and completed error message allows to diagnose the core cause.
For example the message with name of required class or the name of required env variable
or any other message that helps to find solution. FRM-105100 is too general
and in my case ORA_JAVA.LAST_ERROR is just empty
thus I really do not understand where to find the bug.