This post is For Information Only in case someone gets this error in the future and finds this when searching on the error message.
I was running an application which uses the Logos4 COM API to interact with the Logos4 application.
My Logos4 downloaded an update, but as the other application was still running, the upgrade process gave this warning report.
I expect most users would work out or guess what might be going on. But in case not, I have posted this in the hope it might be useful to someone one day.
Solution: Close the other application that interacts with Logos4 if possible, then click OK for the upgrade to process.
In the event that you just click OK, and leave it to sort itself out, it might be OK, but it will be safer and more sure if you can close the other application first.

P.S. Thanks to the Logos Team that this condition is detected by the installer, rather than some bad outcome ...