Question

The 'Open with' feature duplicates my applications every time I install an update. How can I fix this?

Answer 1

To solve this issue, you can try to open the Terminal, 'copy & paste' this in it and hit Enter :

/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/LaunchServices.framework/Versions/A/Support/lsregister -kill -r -domain local -domain system -domain user 

After this, you need to relaunch Finder by right click it while holding down ALT key and select Relaunch. This should fix your problem.