You cannot create FuntLocation task lists without a PM planning plant

What causes this issue?

The master record of the functional location you entered does not
contain a planning plant.

System Response

The system requires a planning plant for functional location task lists,
since maintenance activities are involved.

How to fix this error?

If you are authorized to maintain the master record, enter the planning
plant in the functional location master record.
If you are not authorized to carry out this function, contact your
system administrator.

Error message extract from SAP system. Copyright SAP SE.