This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Profile missing error after Quantum upgrade

  • 6 replies
  • 1 has this problem
  • 19 views
  • Last reply by philipp

more options

I tried to delete all files, resetting the system, resetting Firefox etc. When I deleted profiles (or completely Mozilla folder in AppData) it opens once, and if I close Firefox, it isn't opening once more without deleting all files.

I tried to delete all files, resetting the system, resetting Firefox etc. When I deleted profiles (or completely Mozilla folder in AppData) it opens once, and if I close Firefox, it isn't opening once more without deleting all files.

All Replies (6)

more options

hi Ariaoth, we have seen other users report this problem in two circumstances recently: either if they had an old version of kaspersky security software running on their device or on accounts with usernames containing non-latin characters. would one of these cases apply to you too?

more options

Which account ? I couldn't understand that. By the way, I'm not using old version Kaspersky.

more options

that would be your windows user name...

more options

It have "ı". Maybe it's non-latin but it's my name and surname enrolled in outlook, so I can't change it.

more options

ok, thanks for confirming - our developers are currently looking into the matter in https://bugzilla.mozilla.org/show_bug.cgi?id=1418325 in case you want to follow along there...

more options

hi again, i think we have fixed this issue now with the updated firefox 57.0.1 which is available through https://www.mozilla.org/en-US/firefox/all/