Final entry indicator has not been set in entry sheet &

What causes this issue?

You have attempted to reset the "Final entry" indicator for a service
entry sheet from within the list of entry sheets to be processed.
However, the "Final entry" indicator has not been set in this sheet.

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.