Could not complete this operation. An unknown operating system error has occurred

[roserp45584434]

I'm getting this message when trying to save for web. Using Adobe Photoshop 2021 with Mac Os Catalina 10.15.7

I've done: 

1. Re set preferences of Photoshop
2. Granted Full disk  Access to Photoshop in System preferences
3. Re install the Application 

Any ideas?

1.  

[Barbara Ash]

Are you using the most current update for Photoshop 2021, version 22.4.1?

[roserp45584434]

Yes, I am.

[John Waller]

Lots of discussion about this in some older threads in these forums, mainly Mojave and Catalina.

https://community.adobe.com/t5/photoshop/photoshop-2019-save-for-web-error-mac-os-mojave/td-p/101624...

https://community.adobe.com/t5/photoshop/adobe-save-for-web-error-on-photoshop-21-0-1-macos/td-p/107...

Have you considered upgrading to Big Sur?

Also, have you considered using the newer (recommended) Export As command instead of the legacy Save For Web?

https://creativepro.com/save-and-export-photoshop-files-effectively/

[SDC-Z Account]

Just had this problem. I found the fix... I had an illegal character in one of my slice names. Fix it just now. Worked perfectly.