PROBLEM DESCRIPTION:

for some reason my sessions was kicked out and the patch process didn’t complete. Then, when i tried to re-apply the patch the following error was thrown:

UtilSession failed: Lock file left by a different patch, OPatch will not try re-using the lock file. 

OPatch failed with error code 73

SOLUTION:

remove the patch lock file using the below UNIX command:

rm $ORACLE_HOME/.patch_storage/patch_locked

then try to re-apply the patch again.