This message appears when there is an exception in the code.
To control that exception is needed to add an exception handler to the code.
If there are already exceptions created, mabye there is some option that is missing.
In order to catch this one, it is possible to add at the end of the code "When Others Then" exception. See the structure below:
CREATE [OR REPLACE] PROCEDURE procedure_name
[ (parameter [,parameter]) ]
IS
[declaration_section]
BEGIN
executable_section
EXCEPTION
WHEN exception_name1 THEN
[statements]
WHEN exception_name2 THEN
[statements]
WHEN exception_name_n THEN
[statements]
WHEN OTHERS THEN
[statements]
END [procedure_name];
If you add this exception, then the debugger will jump to this exception.
If not, then the debugger does not have any other option than to exit.