Latest update won't open old projects

Thanks for the update!

"Media - none of it opens, so doesn't matter."

That assumption may or may not be valid, neither of us knows. As it could be related to what media was involved in the project. If you cannot prove it, don't assume it ... best operating assumption is no assumption.

And thanks for supplying the data to I suppose their UserVoice system. In talking with engineers, the biggest problem they have with bug reports is way too many are of the nature of "X is broken, fix it".

If it is something the engineers don't know about, there's nothing there to help them replicate the problem. They can't fix until they can replicate. And frequently that means replicating the exact situation ... hardware, OS, media, effects, and steps in "this" order not "that" order.

Neil

Please, for any report like this give useful data. What is your OS, hardware, media, and typical effects used. All could be the cause of this on your machine. Troubleshooting needs all that data to start puzzling out what's going on.

And realistically, never assume because something happens on your machine, it must also happen on all others. Most of the "major" problems still affect less than half the user base. The vast majority of true bugs affects rather small subsets of users. Because they're specific to certain conditions which all have to be met.

I have no troubles opening older projects on my Ryzen 24-core desktop or Acer Intel-chipped laptop. But I've no way to figure out why it works on mine and not yours because I know nothing whatever about your setup.

Neil

Delete the Media Cache and Media Cache files:
https://community.adobe.com/t5/premiere-pro/faq-how-to-clear-your-media-cache-in-30-seconds-in-premiere-pro-2020/m-p/11017257/thread-id/260446?page=1

Then create a new project and import the old one into it.