Internal error: list of MR reasons cannot be called

What causes this issue?

If the meter reading reason is not clear, an * is displayed. By using
F2 on the meter reading reason field, a list of the corresponding meter
reading reasons, installations, billing date, and meter reading unit is
displayed. Internal error: these values could not be determined.

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?

Error message extract from SAP system. Copyright SAP SE.