The file “Desktop” couldn’t be opened.

Same thing here. And Preview was REALLY wacky yesterday as well as anything I try to save to desktop either says it won't copy and it does anyways, I get this error (no saving) or icons are all white.

Has been going on since my latest desktop OS update - this OS seems to have THE MOST issues non-stop both OS and iOS.

If anyone figured this out let me know!

I have the same issue. I'm simply trying to save a TextEdit file "Test.rtf" to my Desktop. Note that the error message says:

"The file “Desktop” couldn’t be opened." [emphasis mine]

I have confirmed that my permissions are good, both via GUI (right-click > Get Info > Sharing & Permissions) and via Terminal (ls -l)

The file handling library seems to be confusing the folder Desktop for a file. I have the same issue with the Documents folder.

Safe Boot from the HD, (holding Shift key down at startup), does the problem occur in Safe Mode?

Safe mode attempts to repair Disks & clears lots of caches, so if Safe Mode works try again in regular boot.

What was the name of the file you were trying to save?

We'd need more info, or maybe post in the Catalina forum. :)

This issue resolved for me by simply restarting my Mac. The good ol turn it off, turn it back on. :)