Nikon Z7 II raw Won't open in PSE 2020

There is a workaround to add Camera Raw 13.2 to Elements 2020.  See this HelpX article and the warning note.  You can download the Photoshop CC ACR 13.2 installer here.  When you replace your current Camera Raw plug-in, you should rename the Camera Raw.8bi file by adding a tilde to the beginning (~Camera Raw.8bi).  If you do not have a reasonably fast computer, the 13.2 plug-in may not work well for you. But it is worth trying out the workaround so Elements will read your new camera's raw files.  If it doesn't work out, you can always go back to the old plug-in file and use the DNG converter suggested by Michel.

The necessary ACR 13.1 plugin is not yet supported in PSE2021 either.

https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-supported-cameras.html

Your best bet is to download the free Adobe Dngconverter and to wait for a future version of PSE.

That standalone app (not a plugin) will batch convert a whole folder of your raw files to the universal DNG raw format that PSE2020 and older versions can read and edit. A additional batch step, but free and with the same quality.

https://community.adobe.com/t5/photoshop-elements/faq-will-photoshop-elements-work-with-my-camera-or-why-won-t-my-raw-files-open/td-p/4303022

(the download links are currently broken, see

https://helpx.adobe.com/photoshop/using/adobe-dng-converter.html