Add-in Outlook not automatically checked

Last year there was a problem with the Avast add-in in Outlook. Later on that problem was solved, but from then on the add-in is not automatically checked by start-up. Every time I start Outlook I have to activate this manually. I made a clean reinstallation. Removed Avast with the tool “aswclear.exe”, but after reinstallation it still doesn’t work.

I checked the forum and internet for solutions but haven’t found anything. Can somebody help me with this issue. Now it is more annoying than something else.