Fix File Associations in Firefox

Once upon a time I decided that, when clicking links that would require the launching of an external program, I would click the little box that says, "Do this automatically for files like this from now on.". It seemed logical at the time because I was growing tired of always clicking "Yes" for my favorite program.

Unfortunatly, when I decided to change the default behaviour I found no way to do so. In fact, every forum thread said the same thing:

Edit[menu] -> Preferences[menu-item] -> Content[tab] -> File Types Manage[button]

My dialog was empty! Apparently there could be a problem with the mime types but so far I have not bothered dig deeper in that direction. Instead I removed a file that holds my preferences thereby giving me the opportunity to make a new choice. This is silly hack if you have many file associations but hey, it works:

The solution is to delete or rename the "mimeTypes.rdf" file in the Firefox profiles folder. In Ubuntu this file can be found here where <your-profile-name> is the name of your profile:<tt> ~/.mozilla/firefox/<your-profile</tt>-name>/mimeTypes.rdf

First, open a terminal (F12 for Yakuake).

Change to Firefox directory:

cd ~/.mozilla/firefox/

List it's contents so we can find our profile folder:

ls -l

In my case the profiles folder was called dgpozag8.default. Change to the profile folder:

cd <tt>~/.mozilla/firefox/<your-profile</tt>-name>/

Once again, let's list it's content and see if the mineTypes.rdf file is there:

ls -l

Rename the file:

mv mimeTypes.rdf zzz_mimeTypes.rdf

When firefox is opened again it will regenerate the mimeTypes.rdf file.

Restoring the orginal mimeTypes.rdf file

If somthing went wrong we can restore our backup file like so:

mv -i zzz_mimeTypes.rdf mimeTypes.rdf