Battlefield Heroes: Failed to download config file

After several months that I didn't play Battlefield Heroes, I tried to play it again.
But a message box popped saying:

I tried to look up for a solution but didn't find anything that works.
I tried to uninstall the game but it didn't help.

Eventually I deleted the Battlefield Heroes extension from my browser and it solved the problem!

Using Chrome as my browser, I opened the menu -> Tools -> Extensions
and deleted the Battlefield Heroes extension, and restarted the browser.

And now when I hit the "PLAY NOW!" button I don't get this error anymore!

I hope this will help you too!