My after effects 25.6 keeps crashing

This usually happens when the cached render threads or preference files get corrupted. I think reseting AE preferences by holding Shift+Option+Command (Mac) while launching can solve this problem. 

You check your permission of  the account. You use "Run as administrator" (Windows) or sudo open command by Terminal.app (Mac). 

I'm sorry to hear about the crash.

Is it crashing with this particular project? Can you try importing your project into a new one instead of just opening it? If that doesn't work, try moving your file from an external location to an internal (your desktop) and then try to open it.

Let me know what happens.