What operating system are you using?
My guess is Mac OS and my guess is this is an issue related to permissions.
What is the exact text of the error message you receive?
I'm using Windows 10 Pro 64bit 32GB RAM, GTX980 Titan, Intel Core i7-4790 CPU 4.00GHz
The exact text of the message is above (1 and 2)
Sorry my card: Nvidia GTX Titan X
Hello, the problem solved itself. And it worked.
1. In Windows Explorer view of the file set to hidden.
2. Enter the folder Windows -> Fonts. First, select all fonts and copy somewhere on another disk. Then select all and delete. Confirm the message windows.
3. Check whether Adobe After Effects now starts up. In my case it worked.
4. I reset the computer. I copied the font removed and re-pasted into Windows -> Fonts.
After Effects now easily runs with all the fonts that I had;)
Regards and good luck
Thanks for sharing what worked!