this is definitely not the intended behavior of our product and we apologize for the complication.
In order to be able to help you I would like to ask you to send the log files so we can investigate where the problem is.
You can simply send them by executing our log collector utility from this path C:\Program Files (x86)\AVAST Software\Avast Cleanup\tulogcollector.exe assuming that you have still Avast Cleanup installed on your computer.
Just please add your email address there so we can join the logs with your report here.
I have the same problem. Since I have desinstalled Clean Up not only Microsoft Office but other programs present the same message. This is something totally unacceptable! I don’t want to format my computer because of your software! Please, offer us a decent answer to this problem!