Photoshop cs6 save for web not working

Hi all.

I realize this is a very old Photoshop version running on an old mac os 10.12.6, but I'm trying to save some money and have no need for an upgrade.

So my Photoshop CS 6 for some reason suddenly won't save for web. I get the error message "The operation could not be completed. The file or directory could not be found. [OK]"

TWIST:

When I use a different user account on my mac there is no issue, but I don't understand what would be specific to that user account/folder as it relates to Photoshop that would render that feature broken for one account and not the other.

Furthermore, when I use Illustrator cs 6 on my main user account, (the one with the PS issue) it can save for web with no problem.

Possible reasons for this:

1) Dropbox a cloud backup went a little wonky and changed some folder names for my main user accout.

2) I was getting some alert from adobe saying my programs weren't genuine (perhaps as a result of adobe cc being installed long ago) and my prgorams would stop working and I googled and deleted some files in attempt to remedy this which never worked. I stupidly did not make a note of what I deleted and have attempted to restore/compare some files to my time machine back up, but have not had any success. Maybe Adobe/Adobe CC really did manage to mess up my PS.

3) I considered uninstalling and reinstalling PS, however, the installer only allows me to uninstall (i tested with an adobe program I don't use). I found another installer but it says there is conflict with payloads or that a file is missing so it won't launch.

4) I found some possible solutions for this issue on the internet but I was not able to implement any of them (or fully understand them). Some need more explicit instructions for us lesser skilled people.

Thanks in advance and any thoughts would be great. Adobe says they no longer support this and were of no help. Apple attempted but we could not find a solution.