There is a bug in After Effects I have faced for over two years working on different versions of Windows 10 (Home/Pro/Enterprise). In order to recreate the bug you need to be signed up to a user and have AE open. Once you switch user and switch back to the user with AE open, preview stops working. It will render on the timeline but it won't preview and crash as soon as you close it.
Current solution is to save and force quit AE (once you click close it will crash and will take a while to quit).
Tested only on Intel CPUs and NVIDIA GPUs (i7-6700K, 1060GTX - i7-10875H, 2070 RTX - Xeon N/A, Quadro N/A).
I know it's a small bug but it can be very frustrating, whether i'm in the office and having to share a workstation or at home having seperate users for work and personal.
Nothing to do with AE. This is a standard Windows behavior with a user change shutting down drivers and changing security contexts. This is beyond Adobe's control, so it's not a bug in the program(s), it's just bad practice. Happens with many other programs just as well.
I am not - I have only experienced this with AE. Preimere preview works well even after switching users and I have never experience issues with other apps, which is why I assumed it's an AE bug and not Windows.