Profile cannot be loaded
From MozillaZine Knowledge Base
If you attempt to start your Mozilla application and you see a "Profile Missing" dialog with a message that your Firefox, Thunderbird, or SeaMonkey profile cannot be loaded. It may be missing or inaccessible, it usually means that the profile folder referenced in the profiles.ini file is either not accessible or cannot be located.
Note: This error message may sometimes appear after selecting the "Close Firefox" button that was added to the Firefox is already running but is not responding error dialog on Windows, starting in Firefox 34 (bug 1068657). If this happens, simply dismiss the dialog, wait a few seconds, then start Firefox as you normally do. Alternatively, open the Windows Task Manager, end all Firefox processes (or restart the computer) and then start Firefox.
Profile is not accessible or cannot be located
A "Profile Missing" error can occur if you delete, rename or move the profile folder for your Mozilla appication, if you run the application from removable media, or if the profile folder is stored on a network drive (see bug 278860 for the background). To resolve the problem:
If possible, restore the profile folder to its original name and location, so that your Mozilla application can find it. Alternately, you can edit the profiles.ini file to show the changed location, as suggested in the Profile in use article. If you moved the profile folder, another solution is use the Profile Manager to create a new profile that points to the new folder location, by using the "Choose Folder" option during the profile creation process. See Moving your profile folder for details.
Important: If you deleted your only profile folder, have no backup to restore and are now seeing the "profile cannot be loaded" message, you can create a new Firefox, Thunderbird, or SeaMonkey profile and then start your Mozilla application, using one of these methods:
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