Could not set lock on table WAHD(-OVAL)for plant &1

What causes this issue?

The system was unable to set a lock on tables WAHD or WAHD_OVAL.
This could be caused by a process that is currently running, or because
a user is processing a required record at the same time. The system was
unable to load the
<DS:GLOS.70086ED0D946154EBC7C6B32697A9C30>alternative historical data
</> (AHD) for the whole <DS:GLOS.3526BF3BAFAB52B9E10000009B38F974>plant
</>.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Release all locked records for the plant and start the program again.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.