I think you might be having the same problem I was having.
These are the steps I took to fix the issue:
Click on the desktop so that you're in Finder. Click on "Go" in the menu bar and hold the alt/option key to reveal the "Library" folder. Go to Library/Preferences/Adobe/After Effects
You should find a few folders - right click on the folder "14.0" and "Get Info". You might need to click on the lock symbol to be able to change the settings. After you've entered your password, change "Read only" to "Read & Write."
Try opening After Effects again.
Hope this helps.
thanks for the reply but unfortunately that didn't work. It still comes up with the same error. I put Read and Write for all the users. Is that what you were advising? At the bottom of the info page?
Anyone else able to help? Adobe are completely useless right now. Cant believe I pay this much for software and the service is this bad.
Does your older version of AE still work?