Table &1 is being locked by user &2

What causes this issue?

You tried to change or delete entries in table &V1&. This table is
currently being processed by user &V2&.

System Response

The operation could not be executed.

How to fix this error?

Wait until user &V2& has finished processing the table. If this user
is no longer processing the table, delete the lock using transaction
SM12.

Error message extract from SAP system. Copyright SAP SE.