Diagnosis
You want to reset tables in a worklist of SPUMG but currently SPUMG scanjobs are running which could process the selected tables during thereset action.

System Response
Only tables which are not processed (worklist status "In Process") canbe reset. Before the reset of a table a lock is set on the selectedtable to avoid conflicts with running batch jobs. The lock is releasedafter the reset and the table is then processed automatically if acorresponding background job is running.