I got this pmon trace file: What is the problem?

Also there is a "PMON unable to delete process" in the alert log.

*** SESSION ID:(1.1) 2000.12.19.16.13.41.000
*** 2000.12.19.16.13.41.000
found process 5f16a220 pid=60 serial=10 dead
*** 2000.12.19.16.13.41.000
deleting process 5f16a220 pid=60 seq=10
CLEANUP_ROLLBACK_ENTRIES=20 rollback entries processed
deletion of process 5f16a220 pid=60 seq=10 unsuccessful
*** 2000.12.19.16.13.41.000
found process 5f16a220 pid=60 serial=10 dead
*** 2000.12.19.16.13.41.000
deleting process 5f16a220 pid=60 seq=10
CLEANUP_ROLLBACK_ENTRIES=20 rollback entries processed
deletion of process 5f16a220 pid=60 seq=10 unsuccessful
*** 2000.12.19.16.13.41.000
found process 5f16a220 pid=60 serial=10 dead
*** 2000.12.19.16.13.41.000
deleting process 5f16a220 pid=60 seq=10
CLEANUP_ROLLBACK_ENTRIES=20 rollback entries processed
deletion of process 5f16a220 pid=60 seq=10 unsuccessful
*** 2000.12.19.16.13.41.000
found process 5f16a220 pid=60 serial=10 dead
*** 2000.12.19.16.13.41.000
deleting process 5f16a220 pid=60 seq=10
CLEANUP_ROLLBACK_ENTRIES=20 rollback entries processed
deletion of process 5f16a220 pid=60 seq=10 unsuccessful