Firefox The associated helper application does not exist

I recently received the error message “The associated helper application does not exist” whenever I tried to download – and run – a torrent file from within Firefox. The associated helper application is a third party application that is either added to the download actions list be default or when a user is selecting to always open a file type with an application.

There is however no way to add default applications on your own which makes it difficulty if one receives this error message. I first took a look at the Download Actions list only to find out that no torrent entry was in that list. You can take a look at all Download Actions in Firefox by clicking on Tools > Options, then the Content Tab and in there on the Manage button next to File Types.

If you see the file extension in the list you could simply click on change action to change the application that opens it by default. This can be necessary for instance if you switch from one application to another.

My case was a little bit different. Since there was no torrent file type in that list I had to reset the Download Actions to see the window again that asks me what to do with torrent files.

The file mimetypes.rdf handles that. If you delete that file after closing Firefox it will have the result that everything will be reset and the file will be generated again after restarting Firefox.

Firefox will ask you then what it should do with unknown files types. I was able to assign the torrent files again to my torrent client and everything worked fine from then on again.

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Author: Martin Brinkmann, Friday September 7, 2007 -
Tags:associated helper application, firefox file types, mimetypes, mozilla

Responses so far:

1. DM Caveman says:

   September 20, 2007 at 7:28 pm

   Man thanks alot dude you really helped me out .

   Reply
2. Rhiannon says:

   October 19, 2008 at 11:10 pm

   Um I have exactly the same problem, but don’t quite understand the solution-sorry Im abit useless when it comes to computers! Help please!! x

   Reply
3. Anonymous says:

   May 16, 2011 at 9:30 pm

   There is no ‘Manage’ tab under ‘Content’. Another tab perhaps?

   Reply