While trying to save or delete a draft version of communication arrangement, you are getting the error message "Active document has been changed concurrently".
SAP S/4HANA Cloud
Fiori application: Communication Arrangements
This is an expected behavior
If somebody changed the active entity of the communication arrangement (over an api or during the upgrade) after the creation of your draft version of the entity, the draft object will be marked as outdated. And in this case save or delete the draft version is not possible.
Please cancel your draft and click on edit again.
KBA , BC-SRV-APS-COM , Maintain Communication System and Arrangement , Problem