I'm using Windows 10. Before this problem, After Effects didn't start up at all. I've also tried reinstalling Creative Cloud and After Effects but it didn't work.
When I look at the task manager while clicking open in the creative cloud software, it appears but quickly disappears after. Or sometimes it'll appear and sometimes it won't at all.
It usually appears under Adobe CEF Helper. Photoshop works just fine when I open it, but I just bought AE.
Try these steps:
Let us know if this helps.
Are you still facing this problem? If not, let us know how you solved it. If so, please let us know so we can assist you further.