When I opened firefox I was offered that firefox cleans some data. Pressing on it took a long so I killed firefox process from Windows taskmanager (taskmgr). . Next time Firefox was started I got the error (warning):
Your Firefox profile cannot be loaded. It may be missing or inaccessible"
Firefox version is 29.0.1.
Once the dialog, Firefox fails to further open. To fix Your Firefox profile cannot be loaded. It may be missing or inaccessible press windows-key+R to invoke <Open program prompt and type in:
In explorer Window that will pop=up rename the folder labelled "Firefox" to something like old-Firefox.
On next start of firefox, you will be offered to recrate "the missiong profile and it will force Firefox to re-create profile.
If you want to import some of your old data into the new profile afterwards: Recovering important data from an old profile check Recovering important data from an old profile Another approach is to to go to Firefox profile folder and delete profiles.ini, this will also make firefox recreate the file on its next start. Enjoy ! 🙂