Meter reader &1 still used in schedule master record for MR unit &2

What causes this issue?

You tried to delete a meter reader that is still defined in the schedule
master record for the meter reading unit. This is not permitted.

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

System Response

How to fix this error?

Delete the meter reader from the schedule master record before you
delete it from table TE115.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.