Item(s) have been inserted. Number of inserted items: &1.

What causes this issue?

Item(s) has(ve) been inserted into Tax Invoice or Correction Tax Invoice
List.
Number of inserted items: <ZH>&V1&</>.

System Response

This is not an error message.

How to fix this error?

Please, fill necessary information about inserted Item(s) and save
changes to the database table <ZH>/SAPCE/FKUA_TXOP</>.

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.