SAP Message 63554 - Participation ID & & & is blocked by &

Diagnosis
Participation ID &v1& &v2& &v3& is already being processed by userV4.

Procedure
If you want to change the ID you have to wait unit &v4& is finishedprocessing.
You can view the ID. Note, however, that the data on your screen may nolonger be current once &v4& has finished processing.