Elements 9 after Catalina upgrade not usable any more

If your old version won't work on your current OS and you don't want to buy another license, what kind of solution are you looking for?  You can restore your old OS and continue to work with Elements 9 or you can upgrade to Elements 2021. Every version of Elements is a new license.  But, as the owner of a previous version, you get an upgrade discount for the new license purchase.

I'll move the thread to the correct forum

When you chose to go to Catalina (or were forced to), it means all your old apps were trashed. Just like that. It's part of the Joy Of Mac. You need to buy all new software. PERHAPS there will be an upgrade price IF you still have your old serial number (don't share it with anyone!!) Warning, scammers may contact you privately pretending to be Adobe staff. Adobe will never send you a private message asking you to email an account that isn't @17309390, or use Skype. Adobe never ask you for their password. These scammers want your Adobe info, credit cards, your money and control of your computer, please take care.

Please post Photoshop Elements related queries over at 

https://community.adobe.com/t5/photoshop-elements/bd-p/photoshop-elements?page=1&sort=latest_replies&filter=all

See for yourself if your OS meets the System Requirements of PSE 9: 

https://helpx.adobe.com/photoshop-elements/kb/system-requirements.html#main_Photoshop_Elements_9_0