Open uTorrent options and make sure it is the default for torrent downloads.

Unfortunately, this is not a solution.

Of course, uTorrent is set as the default application in Windows. Interestingly, the magnet download starts properly.

I tried it with a clean Win10 / 64 installation, there is the same error, but only for Firefox 83, 84.

Type about:preferences#general<enter> in the address bar. Look under Applications. Are torrents listed?

I once had a problem where the torrent links were not calling the program. It turns out the links were being downloaded but did not auto-call the torrent program. Check your download folder.

Of course it is set as default (photo attached, the laguage Hungarian)

I tried Transmission 3.0. Same error, firefox does not start the torrent client. The difference is that no appcrash entry is placed in the WER folder.

I would like to emphasize that there is no change in either the hardware or the software installed. If I go back to the older FF 82 version, it works fine. Interestingly, it is also good with the latest version 78.6esr. I'm sure there may only be an error in the new version of Firefox. There is a need for some deeper examination.

Interestingly, this problem was not reported by another User.

I called for more help.

@FredMcD

I would like to know what happened to finding the error described. Unfortunately, the latest version of Firefox just released is also flawed. Fortunately, version 78.6.0esr works fine. Please investigate what is wrong and it would be nice if they could fix it.

Is there a chance they can say some solution? It's been two weeks again. The latest version of Firefox also seems to be faulty. :(

I called for more help. That's all I can do.

I would like to point out that the version 78.7.0esr just released also works correctly. The new version 85.0 is still faulty. Maybe you can find the error.

You can fille a bug report here: https://bugzilla.mozilla.org/

See Bugzilla etiquette before commenting in bug reports. https://bugzilla.mozilla.org/page.cgi?id=etiquette.html

I took note of the new advice I received a month after the questioning. That is, register on another forum, describe the same question as here. I won't do it. For you as a Mozilla employee, this might be easier. I might even get some good advice on that forum to go to a third address. I don’t understand why this forum is when posted from here to another location. Maybe they're smarter there? All this does not shed a good light on Mozilla customer service activities.

Hi,

The people who answer questions here, for the most part, are other users volunteering their time (like me), not Mozilla employees or Firefox developers.

If you need to file a bug report or feature request for Firefox and other Mozilla products, see File a bug report or feature request for Mozilla products for details.

Thanks. I understand.

I found the solution that uTorrent does not start when downloading a torrent file in newer Release versions of Firefox, while it ends in older and ESR versions.

The error was caused by moving the Temp and Tmp folders to Windows \ Temp in Windows System Preferences (originally User-Appdata-Local). All other programs on the machine work fine, except for newer versions of Firefox.

After that, I would like to know what could be wrong with Firerfox, i.e. how it handles the Temp and Tmp folders.

That was very good work. Well Done. Please flag your last post as Solved Problem as this can help others with similar problems.

As to your question, I suggest asking a new question.

I found the solution that uTorrent does not start when downloading a torrent file in newer Release versions of Firefox, while it ends in older and ESR versions. The error was caused by moving the Temp and Tmp folders to Windows \ Temp in Windows System Preferences (originally User-Appdata-Local). All other programs on the machine work fine, except for newer versions of Firefox. After that, I would like to know what could be wrong with Firerfox, i.e. how it handles the Temp and Tmp folders.

Firefox processes run with medium to low integrity to minimize the ability of web content to hack the system. If there is a privilege problem with the changed folder used for temporary downloads, then I would expect all cases where you choose Open in the download dialog to fail. Is it only using Open with torrent files that fails, or does the problem affect other kinds of files that you choose to "Open" rather than "Save"?

I have not experienced this type of problem.