Revision &1 in plant &2 does not exist

What causes this issue?

You have selected a revision that does not exist in the specified
planning plant.
Note that the planning plant of the planner group must be identical to
the planning plant of the revision. The plant of the revision is always
automatically copied into the planning plant of the planner group.

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?

Assign a vlaid planning plant to the revision and, if necessary, to the
planner group.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.