Device: &1 Reg. &2: Several meter readings with same meter reading time

What causes this issue?

The meter reading result was not saved as this would mean that several
meter readings would exist for the same time on the same day. This is
not possible for billing related reasons and therefore billing is
terminated.

System Response

This is dealt with automatically if it concerns meter reading reasons,
for which the meter reading time is assigned by the system.

How to fix this error?

Ensure that a register does not have more than one meter reading in the
system for any given meter reading time.
The following procedures exist for the different meter reading reasons:
Meter reading reasons, for which the system assigns meter reading times
automatically
Meter reading reasons, for which the system does not assign meter
reading times. The person responsible must decide the sequence in which
the meter reading reasons are entered.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.