Diagnosis
Tasks, rules, and workflow definitions require an ID that is uniquethroughout all systems and clients. In this way, you can ensure thatyou can transport these objects from one system into another at anytime (without restrictions). From a technical point of view, theuniqueness of the ID is ensured by what is known as a "prefix number".You can define a separate prefix number for every system and everyclient in table T78NR.

System Response
If a prefix number is not defined in the client in which you arecurrently working, it is not possible to maintain (maintenanceterminates).

Procedure
Maintain table T78NR in Customizing, andcreate an entry for the system in question and the current client.