Not all meter readings results have been entered

What causes this issue?

You have not yet entered a meter reading for all meter reading
documents.
Gor the following transactions it is imperative that you enter meter
readings:
Device installation/removal/replacement
Device modification
Rate type change, if a meter reading is obligatory.
However, interim meter readings must only be entered if they coincide
with a meter reading <LS>Change Installation Structure</> (meter reading
reason 17).

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?

Enter the missing meter reading results.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.