AE CS6 didn't get open by Mavericks and authomatic update under help didn't show any required update for AE. After many search in your forum I found the links to the updates for different verisons of AE CS6. Mine is 11.0.2 but the update (AfterEffectsTrial-11.0.2-mul-AdobeUpdate.dmg ) didn't get install and I kept receiving the folllowing message.
Installation failed. Error Code: U44M2P7
Finally I updated whatever was available under help-
tried the same file for 11.0.2 and failed again.
And now Mavericks can open AE CS6 .
The After Effects CS6 (11.0.3) update is the one that added the fix needed for Mavericks. So, installing either the 11.0.3 update or the 11.0.4 update is necessary for After Effects CS6 Because the 11.0.4 update includes even more fixes, that is the one that should be used.
For After Effects CC, the 12.0.1 update was the one that added the Mavericks fix. Of course, you should use the more recent 12.2.1 update, which has even more fixes.
Links are here: