I've recently updated my OS from Ubuntu 20.04 to 21.10. Since then, I got some troubles to download files in Firefox and get this error message:

Downloading could not be saved, because an unknown error occurred. Try saving to a different location.

Sometimes, downloading works fine but I get a firefox.tmp folder in my Downloads folder.

I've found this article related to this problem: https://windowsreport.com/could-not-be-saved-unknown-error-firefox/. However, I don't see the "status" in about:config.

Many thanks for your help!

CodePudding user response：

With the firefox snap package, temporary files during downloading are stored under Downloads/firefox.tmp. If this folder is deleted, it is no more possible to download file and the error message shows up.

The solution is then to keep the firefox.tmp folder or to use the firefox .deb package.