Today after updating Firefox from version 56 to 57 I'm getting constantly message saying "Your Firefox profile cannot be loaded. It may be missing or inaccessible". It show's up few times when starting Firefox and everytime I open any page in new tab that includes add-on, history, etc. (openning only new tab doesn't show this message). This is what I tried without success: -> Complete reinstalling with pc restart. -> https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles -> https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible -> Wiping out all mozilla folders from roaming, local and locallow and then creating new profile.