Problems with .mov files after Big Sur upgrade

[MaryAnnD1007]

I just started working on a movie I haven't opened for a week or two. All of the .mov videos are missing from project assets. The cursor stops at the first video during play - but you can hear the sound associated with the video. The app asks where the videos are, I navigate to the file and click on it; it asks for the same .mov file again. 

I tried to delete the movie files and try again. There are errors on every single file. These are the same exact files, with no editing, since the last time I worked on this movie. The videos play just fine outside of the app. 

I opened a new movie and tried to import the files in question. I got errors on every .mov file. 

I did upgrade to Big Sur since the last time I worked on the video. That is literally the only thing that has changed. 

Help!

[Bill Sprague]

What version of Premiere Elements are you using?  

[MaryAnnD1007]

2020

[John T Smith]

>upgrade to Big Sur

You should always wait to update your Mac operating system until you verify that the non-Apple programs you use are going to work properly... not only Adobe programs, the 2nd link below is about Avid... aimed at video editing, but it is a warning for ALL non-Apple program users

These are not specifically about Premiere Elements, but the idea is the same no matter which program

https://community.adobe.com/t5/download-install/can-i-run-my-adobe-applications-in-macos-11-big-sur/...
https://ymcinema.com/2020/11/15/premiere-pro-and-avid-editors-do-not-upgrade-to-macos-big-sur-yet/
https://tidbits.com/2020/11/13/big-sur-is-here-but-we-suggest-you-say-no-sir-for-now/
And, Apple's update sometimes isn't even compatible with itself
https://www.macworld.co.uk/news/macos-big-sur-bricks-older-macbook-pro-models-3798046/

I do NOT know if these links will work with sur
https://macpaw.com/how-to/downgrade-from-catalina or
https://www.macworld.co.uk/how-to/mac-software/downgrade-macos-3581872/

[MaryAnnD1007]

Wow! So you're saying Premiere is not going to update to work with the newest Mac software updates?  I have only had this 2020 license for a couple of months. What a terrible shame. Who knew buying from Adobe was a waste of money?

This is enough to encourage me to move to a different system. 

[John T Smith]

As far as I know Adobe does not go back and make changes to already issued versions of Premiere Elements (someone may come along with different information)

I don't know the exact timing, but you MAY qualify for a free upgrade to the current version 2021

My point was that upgrading to the latest Apple operating system is sometimes going to require new software... if you don't want to upgrade your version of PrElements you'll need to go back an operating system version... IF that is even possible

Also, you should be talking to Apple about not maintaining compatibility with previous versions of programs

[MaryAnnD1007]

Really - there are no program updates to Premiere 2020? ...ever?  

Honestly, I don't think it's Apple's job to check every program ever written to be sure it's back compatible. It is the responsibility of software folks to update their code as needed to continue to work with updates to operating systems.

[John T Smith]

>no program updates to Premiere 2020? ...ever?

Again, this is only MY understanding, so someone else may come along with better information

BUT... my understanding is that each Premiere Elements version is "locked" at a certain time, and once a version is issued it is not updated... especially after a new version is released... so, not that 2021 is out 2020 will never be changed

And, Adobe does do updates for newer operating systems... which would be version 2021