While applying an online patch today, ADOP failed during the apply phase with the error
AutoPatch error: You must be in Maintenance Mode to apply patches.
You can use the AD Administration Utility to set Maintenance Mode.
Now, this message should never come in an online patch as oracle did away with the Maintenance mode feature with 12.2.4. So what could be the problem?
Several hours and 100’s of log files later, it was found that the tnsnames.ora did not have the proper entry for <SID>_PATCH tns entry. It should have the EBS_PATCH service name in it. The fix was quick – my entry went from
ORCL = (DESCRIPTION=
ORCL_PATCH = (DESCRIPTION=
Lo & behold – APPLY phase went through without any issues. Now, if only Oracle had more meaningful error messages 🙂