Premiere Elements 2020 Will Not Launch

What exactly does "the program will not start" mean ? Do you get any error messages, or what is the exact behaviour ?

Have you tried opening it directly from the exe file in Program Files?

Try right click > Run as administrator.

Can you list which of the many recommendations you've tried?

It sounds like the various routine updates in your computer's operating system have somehow disconnected the needed links to the PrE.   You may have to uninstall and reinstall.  But,  without more information, I'm only guessing in the blind.  

Mac or Windows, and which version of the operating system?

If Windows (I don't do Mac) have you updated since the program last worked?

What is your hardware, and is your video driver up to date?

If nVidia, nVidia Driver Downloads https://www.nvidia.com/Download/index.aspx?lang=en-us
-for all Adobe programs use the STUDIO driver, not the GAMING driver
-To achieve the highest level of reliability, Studio Drivers undergo extensive
-testing against multi-app creator workflows and multiple revisions of the top
-creative applications from Adobe to Autodesk and beyond

in the future, to find the best place to post your message, use the list here, https://community.adobe.com/

p.s. i don't think the adobe website, and forums in particular, are easy to navigate, so don't spend a lot of time searching that forum list. do your best and we'll move the post (like this one has already been moved) if it helps you get responses.

<"moved from using the community bugs">