Predecessor activity "&1" has not been completed correctly

What causes this issue?

You are trying to start an activity that cannot run until its
predecessor activity "&V1&" (program &V2&) has finished with status "OK"
or "WRG".

System Response

The activity cannot be started.

How to fix this error?

Check the status of the predecessor activity and remove any errors
specified in its log.

Error message extract from SAP system. Copyright SAP SE.