Hi richard78024, is this a continuation of your earlier problem or is it a new problem after the earlier problem was resolved? In order to understand the whole situation, please keep the related discussion together.

https://support.mozilla.org/questions/1151491

Is this really about "Cannot find configuration file" or about "Cannot find profile" like the title in the other thread?

• [/questions/1151491] Did a new install but will not start, error message says "Cannot find profile"

Quote:Error message "Cannot find configuration file"

With this error message you need to delete the Firefox program folder because there is likely an additional file in the "defaults/pref" folder that specifies using a mozilla.cfg file and where only the channel-prefs.js file should be present.

Delete the Firefox program folder and do a clean reinstall.

• (32 bit Windows) "C:\Program Files\Mozilla Firefox\"
• (64 bit Windows) "C:\Program Files (x86)\Mozilla Firefox\"

You can find the full version of the current Firefox release (50.1.0) in all languages and all operating systems here:

• https://www.mozilla.org/en-US/firefox/all/
• https://www.mozilla.org/en-US/firefox/notes/

OK. I have tried all recommendations and still getting same error message: "Cannot find configuration file. Contact your system administrator"

That message can indicate a problem in the Firefox program folder. If you haven't already, please try:

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent or alien code files). As described below, this process does not disturb your existing settings. You do not need to uninstall Firefox first.

It only takes a few minutes.

(A) Download a fresh installer for Firefox 50.1.0 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.) Choose the "Windows" version (32-bit) rather than the 64-bit version for maximum plugin compatibility (and of course for 32-bit Windows systems).

(B) Exit out of Firefox (if applicable).

(C) Using Windows Explorer/My Computer, rename the program folder as follows:

32-bit Firefox on 64-bit Windows: Rename

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

Other combinations: Rename

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(D) Run the installer you downloaded in step (A). It should automatically connect to your existing settings.

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Will Firefox start?

SUCCESS!!!! Thank You!

Did this work with my above reply?

Did you verify that the Firefox program folder was gone?