I had not experienced this issue before I have the latest AE CC 2015.8.1 running
Software OS X 10.9.5 2.7 Ghz 12 core Xeon E5 (13F34) 64 GB Graphics AMD FirePro D700 6144 Mb
Basically I cant do any work. On my 4K monitor it takes 10 minuets to open a project which is just small and than the comp window is just grey out. This mac only has Adobe Cloud Apps. I had to downgrade back to Mavericks as Premiere will not work in El Capitan and Yosemite so I m not sure what to do next.
Any help appreciated. I un installed AE re isntalled and nothing.
Trashed preferences too. Nothing still same error.
For anyone else experiencing something similar I think I found the issue. It was a Red Giant Universe problem. The plug ins need it updating. So I updated to version 2 and now After Effects work.