symbolic link in path to Profile.init can cause Profile Missing... problem
Ubuntu linux 13.10 - I kept getting the Profile Missing or Incomplete message after I moved my home directory to a second disk and created a symbolic link to redirect to the new location. To be precise, the new home directory was:
/data/home/tbr
and the old /home directory was replaced with a symbolic link:
/home --> ./data/home
The rest of ubuntu (including Thunderbird) seemed to work fine, but Firefox could not find the old profile, or successfully create a new one (message was something like 'file access denied'), despite a lot of playing around with permissions, purging and re-installing Firefox etc. Booting into recovery mode and changing things to actually mount the second disk on /home (i.e. no symbolic link involved) cured the problem.