My Authentication box was not showing username and Password dialog. Please check the attachment.
Please help
That’s because in the Admin settings panel you’ve selected “Customers login via email as username” (down the bottom, like the text)
This is big mistake i have done. I change the setting to username, but now i forget my username and i can’t access to admin panel please help me. there is any solution to see the username on any file. 
lol…that was just about as embarrassing as my bug post…lol