The Post Timesheet job has been run and all timesheets except one have been posted. The affected timesheet remains on an Approved status
In the log files you see warnings like:
WARN 2020-01-06 14:23:58,977 [https-jsse-nio2-2443-exec-5] niku.xql2 (clarity:admin:17981279__991BA6FA-3E10-4199-BF2C-3D55DA733464:PPM_REST_API) Lock ~prTimeEntry held by user 5000000 requested by user 5000000
WARN 2020-01-06 14:23:59,081 [https-jsse-nio2-2443-exec-5] niku.xql2 (clarity:admin:17981279__991BA6FA-3E10-4199-BF2C-3D55DA733464:PPM_REST_API) Lock ~prTimeEntry held by user 5000000 requested by user 5000000
This is caused by a prtimesheet lock on the prlock table.
If the above doesn't help, see also: Approved timesheets not posting - master KB of known issues