Fixing ‘”A newer version of this app is already installed on this computer” Alert

I’ve just got a nice alert, while trying to install a Mac App from the AppStore, saying the following:

"A newer version of this app is already installed on this computer."

Solutions?

  1. Nuke the app’s Xcode build folder.

    Location: ~/Library/Developer/Xcode/DerivedData/

  2. Execute the following command:

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

Now you should be good to go!