P: File extension (ex. jpg) not changing during format change after upgrade to macOS 10.15 Catalina

Everyone has this problem Kate... 😕😕

I'm trying to save a pdf from Photoshop. I have the latest version of Photoshop, but just upgraded to Catalina (I didn't see anything warning me not to upgrade yet). When I save as, I drop down to pdf but the file ext doesn't change from psd and it saves to a psd file. If I try and open the psd file it gives an error. Anyone had this problem?

A quick fix would be to edit your photos as normal and use a file converter that batch changes .psd to .jpg 
Google psd to jpeg batch

You can type the extension in yourself when saving the file.  Make sure you choose the correct file format in the pulldown menu.

MacPaw has this article for reference, but I would rather just make a bootable Mojave installation on an external drive and keep Catalina -- this sounds like a big hassle to me!!!   Good luck.  https://macpaw.com/how-to/downgrade-from-catalina

Does anyone know how to downgrade to previous OS?

File>Export>Save for Web (Legacy) - Cmd-Opt-Shift-S doesn't work for me. I just chatted with Photoshop. This is a known issue and for now the workaround is to  manually add the extension in finder. Fun times! They are working on a fix.

For now, as a quick workaround, File>Export>Save for Web (Legacy) - Cmd-Opt-Shift-S still keep the .jpg extension.

The problems seem to be different for different users.  I started out on Windows and switched to Mac and would NEVER go back to Windows.  My problems with Catalina are really quite small, and I'm certain that they will be resolved between Adobe and Apple, and the developers, in a reasonable time.  HAVE A GREAT DAY!

 > I updated to iPad OS for the sake of using a portable drive with it, and it appears by gaining that, I sacrificed the ability to even see the files in folders  that have more than 100 files in them.

Ahh Cristen, it's a nightmare for sure!  I'm sorry Apple Engineers haven't been in contact with you. I have come across so many problems with file formats, photos, notes and today alone I've sent another 3 files to Apple Support. I've got an open link with them for 7 days so I guess they might be taking the issue seriously.

The iOS 13 upgrade has really caused issues with file incompatibility.

Thank heavens I don't own a Mac!  Sorry Mac users! I sure feel for you with the issues your having with Catalina OS