Update process currently running in Software Update Manager (SUM)

What causes this issue?

The Software Update Manager (SUM) is currently used to update the SAP
System.

System Response

The System does not allow the execution of parallel update processes by
other tools, like the Support Package Manager or the Add-On Installation
Tool. Therefore, you cannot define and import a queue using these tools.

How to fix this error?

Check the currenty running update process in the Software Update Manager
and complete it there.

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.