Icedragon will not start after new installation

I just installed Icedragon without error and it will not start.
I get this message when trying to run it: “IceDragon is already running, but is not responding. To open a new window, you must first close the existing IceDragon process, or restart your system.”

I tried re-starting my computer and still the same message. I have both Firefox and Palemoon, but they have not been started when I try and run Icedragon. I cannot see anything in taskmanager that looks like a problem, and far as I can see, Icedragon is not running. So why is Icedragon not working?

I had this same issue with both IceDragon and Firefox. It seems they didn’t shut down properly and here is what I did to fix the issue…

Do a search on your computer for "%APPDATA%\Comodo\IceDragon\Profiles
Open your default profile folder (should look something like “gfkrt644.default”)
Delete the “parent.lock” file
Start IceDragon

I had to do this for Firefox as well…same process.

From Mozilla Support…

[i]Remove the profile lock file

If restarting the computer or ending Firefox processes didn’t help, it may be that Firefox previously exited without deleting the lock file.

Restart your computer. After it restarts, don’t try to start Firefox.
Go to your Firefox profile folder - see Finding your profile without opening Firefox.
Delete the parent.lock file.
If you attempt to delete the parent.lock file and receive the error, “Cannot delete parent: The file or directory is corrupted and unreadable”, restart the computer and check your drive for errors (see How to perform disk error checking in Windows XP or Check a drive for errors in Windows Vista/7).[/i]