Common problem. First, upgrade AE to the latest version. Second browse to your Users/Doug/Library/Preferences/Adobe/After Effects folder, open the info panel for that folder and change the permissions to read write for everybody or just delete the entire folder and AE should build a new one on relaunch.
Thanks Rick. AE is already on the latest edition. The odd thing is I can't seem to find the 'Library' folder... but when I try to create a new 'Library' folder it says "there is already a folder named Library" ...Maybe I just don't have permission to see it!?
I do (for some reason) have the path 'Users/Doug/Documents/Adobe/After Effects/13.2/dummy' Not sure if this should be here or not...
Apple hides the Library folder by default. It's there, but hidden. Search the Internet for instructions to show it.