Hi Kwena, sorry to hear about this problem. Do you recall how it started? Was there a severe crash, or did you try the Refresh feature and it never completed?

Also, your browser reported that it is Firefox 59 running on Windows 8.1. Is that a different system?

If Firefox cannot start because it cannot file a profile:

Call up the Windows Run dialog using either Windows key + R or on the lower part of the windows 8.1 start page, it's somewhere in that huge list of apps.

In the dialog, paste the following and press Enter to execute it:

firefox.exe -P

That should call up the Profile Manager. Don't delete anything here!

Any time you want to switch profiles, exit Firefox and return to this dialog.

Click the Create Profile button, assign a name like March2018, and skip the option to relocate the profile folder. After creating the profile, select it and start Firefox in that profile.

That should get Firefox going with a "factory fresh" profile. The next step would be to try to recover your old data. If you're interested in help with that, let us know.

Hi. I don't recall any particular incident except that I barely closed firefox because I didn't want to lose the work I was doing. Then suddenly the "profile missing" tabs started out of nowhere. I tried all what you're suggesting and more on the troubleshooting help with no rescue.

What do you mean "no rescue"? Are you unable to start Firefox because it says it cannot find your profile? What is the exact error message you get right now?

One thing you could try:

First, turn on viewing of hidden files and folders:

https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files

Second, hide the Firefox folders here:

C:\Users\your-user-name\AppData\Roaming\Mozilla\

right-click Firefox > Rename to FirefoxOLD

C:\Users\your-user-name\AppData\Local\Mozilla\

right-click Firefox > Rename to FirefoxOLD

When Firefox starts it should generate a new Firefox folder with a new profile.