How To Fix VA159 - Set operations &1 &2 &3 could not be executed (version &4 completed)

SAP Error Message - Details

• Message type: E = Error

• Message class: VA - Output for CAS Sales Activities

• Message number: 159

• Message text: Set operations &1 &2 &3 could not be executed (version &4 completed)

What causes this issue?

The set operation could not be carried out because the version to be
changes has the status 'completed'. Versions with this status cannot be
edited.

How to fix this error?

In order to change this version, you must cancel the 'completed'
status.

Error message extract from SAP system. Copyright SAP SE.