What?(Oops, try again. It looks like your header's font-size is 16px instead of 16px.)

im confused. Can somebody please help me?

Post your code and the question.

besides your code, make sure your browser zoom is set to 100% (ctrl + 0 or cmd + 0 for mac)

This has been an issue for over a year now, at least for me. It just refuses to accept it.

Please make a new topic with your code plus error message and question so somoene can help you