Why a Blank Profile?
Very often, when experiencing a problem with Firefox extension, some particular settings or other extensions in your profile may be interfering. It is an extremely powerful debugging tool to try to reproduce the problem in a blank profile, and see if it still happens. If it does, it's a problem with just that extension. If it doesn't, the problem is to locate the conflict.
Testing For a Conflict
To create a blank profile, follow these instructions. You can also follow these instructions from Mozilla, with screenshots. (Note, substitute Thunderbird for Firefox anywhere below, for extensions for that program.)
- Close any running Firefox windows.
- Start Firefox with the -profilemanager command line argument.
- For Windows, click Start, Run... and type: firefox -profilemanager, then click OK.
- For linux and mac, just type ./firefox -profilemanager (from within the directory Firefox is installed in, varies by distribution.)
- Select Create Profile..., click Next, and in the box that comes up type a name, like "test". Click Finish.
- Select the profile you just created, and select Start Firefox.
After testing is complete, repeat step two, but select the original (probably "default") profile to switch back. This way, you don't have to install/uninstall or disable all of your existing extensions!
Finding the Conflict
If the blank profile does resolve the problem, it is usually best to start installing all of your regular extensions, one at a time. After each one, check if the problem comes back. When it does, the last extension installed is the culprit.
