After Effects Crashing? Not sure

[pixel 2000]

Hi I have encountered following problems with Ae.

My Ae preview panel will start freezing after a few minutes of work (eg add some videos) and trying to do something further. There is no changes on preview panel even that I try to add video or something, it totally freeze. 

Then, when I click on close to close the program and intended to restart, it says After Effects not responding. 

Another problem is, when I opened an existing Ae file,  nothing show on the preview panel like below. Anyone can help?

[Anna217759694l7y]

I have the same problem.

Anything we can do? Besides Purging, deleting temp files, upgrading, uninstalling, reinstalling, updating drivers?

[pixel 2000]

Hi I did whatever you suggested. 😂 But nothing worked.