Save for web error - Mac OS Catalina

[KeyopsTech]

Hello everyone,

I have an issue saving gif for web with my OS to Catalina (10.15.2).

When I try to save, there's a message saying :

"Adobe save for web error. Could not complete this operation. An unknown operating system error has occured."

I tried to delete "save for web prefs.psp" but nothing has changed.

[defaultnikz1y6pdpal]

Here's what worked for me. 

When exporting, check your image size. You can see below that my pixel width was 8192. I needed to make the pixel size smaller. I kept the same proportions  (Keep the chain icon locked), and lowered it to 4,000 (pictured below as well).

The error message disappeared and I got my gif!

Hope this helps. 

[TinyHousePhoto]

I just had this same issue happen for the past two weeks. My friend walked me through it. I recently signed up for Dropbox Backup and apparently that was the issue. I had to disconnect Dropbox Backup to make my Photoshop work correctly. 

Grateful we found the problem, but WHAT THE HECK. How annoying. 

[Fortnum & Mason]

The way I resolved this issue for a user was to provide full disk access to photoshop - No error

GIF animated perfectely fine. 

[Justin Mensah]

I recently had this same problem. I couldn't save for web on certain files, but it worked for other files so I knew it wasn't an OS issue. I tried restarting, checked the image size and none of that worked. I then gave Photoshop Accessibility in Security & Privacy and still that didn't work. What worked for me was going into my Preferences -- Adobe Photoshop (Year) Preference Settings and deleting 'Save for Web Prefs.psp' and also deleting Preferences -- Adobe Save for Web 13.0 Prefs. Restart and tried saving again and it was successful.

Hope this helps someone.