I can open and switch to all other applications. I have included a video.
I have done the following:
Restarted
Cleared Application Cache
Rebuild macOS Metadata
Stopped Alfred and removed ~/Library/Application Support/Alfred 3 and started
After each one the issue is still happening.
https://youtu.be/4k91ilTyrQQ
OSX: 10.14.1
Alfred: 3.7 [938]