Blueprint &1 is already being executed by &4

What causes this issue?

Blueprint &V1& for configuration object &V2& with configuration key
&V3& is currently locked by user &V4&.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Contact user &V4& and repeat the transaction.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.