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Firefox 21.0 won't start on my Ubuntu 12.04 system with error message:

Your Firefox profile cannot be loaded. It may be missing or inaccessible.

I have tried everything including removing the ~/.mozilla folder, reinstalling firefox, setting the owner and user rights of the ~/.mozilla folder. Nothing works!

What am I missing? Is there any other system folder I have to change the user rights on?

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migrated from Jun 6 '13 at 18:36

This question came from our site for professional and enthusiast programmers.

try running firefox -P and creating a new profile – strugee Jun 6 '13 at 18:39

I found that both my ~/.cache/mozilla and ~/.mozilla directory trees were owned by root:root and should have owned by username:group. This was coming off a fresh install of 12.04 LTS therefore I suspect a bug in a setup script.

Make sure you are in your home directory and your own userid:

sudo chown -R YourUsername:YourGroupname ./.mozilla
sudo chown -R YourUsername:YourGroupname ./.cache/mozilla

Replace YourUsername with your own username, and YourGroupname with your preferred group which by default is the same name as your username.

The .mozilla directory was easy to find, however the .cache directory was not obvious to me. I was able find firefox was looking at the .cache directory by starting firefox and leaving that error message dialog up, and while firefox was still running in a terminal entering: lsof | grep firefox

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Although you seem to have set permissions it sounds exactly like a permission problem. Have a look at this thread and the official Firefox Support forum with the same problem:

Firefox won't start
Use the Profile Manager to create and remove Firefox profiles

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  1. Delete your .mozilla/ folder.
  2. Download the Firefox zip file from Mozilla:
  3. Unzip it
  4. Run ./firefox from the terminal

This will automatically generate a new profile for you. Close Firefox.

You can now click on the Firefox icon and be able to use it as before.

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Close your firefox and then run the following in the terminal:

sudo chown -R $USER:$USER ~/.mozilla
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You dont have to do anything only need to delete firefox folder from .mozilla/ (Home/.mozila)

And then just try to run firefox it will automaticaly recreat the new profile in same location and your firefox will run.

Thanks, Sandesh Joshi

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Remove current profile by using following command:

~/.mozilla/firefox# rm profiles.ini   

after that create new profile as:

~/.mozilla/firefox# firefox -P  

and follow the wizard's instructions.

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