This service entry sheet was created externally and cannot be changed.

What causes this issue?

This service entry sheet was created from an external system. You cannot
change it within this system.

System Response

You can only display this service entry sheet in this system.

How to fix this error?

If you need to change this service entry sheet, please change it in the
system in which it was created.

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.