Videos Are Not Playing

You can use the current public version (Pr 24.1) which will co-exisit with the Beta version. But there is no direct way for Public Beta users to roll back from one Beta build to an earlier one. How bad is this blocking your real-world workflow?

This did not happen until the update this past Friday. Is there was way to go back to that version?

You will need to render things at export anyways. It requires no work on your part, but you will have to wait while things re-conform and such... for each project what shared that system's Media Cache.

The Media Cache will not destroy or delete your project or your source files. But you will have to the rebuild all of the preview files that are needed to smoothly play back any of your projects. That takes time but it won't harm the project or media in the end.

Opening it with shift did not resolve the problelm. I restarted my computer and that didn't help either. If I cleared my media cache then wouldn't I lose my project? I'm in front of my computer now.

OK my test environment is on par with that. So I might just need a test file.
Also, if you're in a position to do so, does it resolve the problem if you clear the media cache or reset other things on that system? To see the full list of Reset options, hold shift (or any other modifier) while launching Pr.

 No clips will play

What build of Pr are you using (the About Pr Pro box will tell you)?
What OS + version are you using?
Can you send me a SHORT (small size) video clip that causes the problem for you?