Please help me! I'm unable to open any files in After Effects. Whenever I try, it just creates a cop

Hola, lo que deberías intentar hacer es restaurar el programa (presiona CMD + ALT + Shift) mientras inicias el programa, luego intenta abrir una de las copias que se crean. Si aun así, el problema persiste, intenta con una copia de seguridad del proyecto, si aún persiste. Eso debería solucionar el problema

Hey Carlos,

A user experiencing a similar issue was able to narrow it down to a font. Could you temporarily deactivate your fonts and let us know if you still see the problem? To do so, open the Creative Cloud App > Fonts, click on the menu with three dots in the upper right corner, and select Deactivate all fonts. Let us know if that makes any difference. 

Thanks,

Ishan

You have a corrupted or incompatible project file that is causing the crash. You could try creating a new project instead of opening one, then enable the Caps Lock key and import the problem composition (Ctrl/Cmnd + i, or File/Import). If the composition has a lot of nested comps (pre-comps) start by opening the pre-comps from the Project panel and releasing Caps Lock. You might be able to find the comp that is causing the crash.

A corrupted font could also cause the problem. You might want to start by clearing your added fonts. 

The problem could also be caused by a bad GPU Driver or a problematic AE build. You can use the Creative Cloud app to roll back your AE version or even install a previous version to check the app.