Oracle Error Message
ORA-12495: cannot disable an enabled level, category, or release category
Reason for the Error
You attempted to disable a level, category, or release category that had previously been enabled. An enabled label definition may be exist in some database label, so cannot be disabled.
Solution
If the label definition is no longer valid, change its name to one that identifies it as invalid. When any labels are converted to character strings, the new label definition will be used.