Fantastic app however for the last few months, when ever my AC crashes, does not start, race cancelled, etc, once I remove or deactivate this app from within Content Manager, The game suddenly works again. I have no idea why this is happening. Another guy had the same problem on Steam and this solution worked for him too.
I will say that the above fixes Content Manager and allows me to play but for some reason, when starting AC (the original launcher) from steam, the game is stuck on "Loading car metadate 100%"
It's weird how CM mess up the install for some, but that's on the CM devs, not me. :-)