2 Minutes Ago I tried to change my skin but it said i answered wrong the security questions.
and then i tried to retype them again it didnt work and i left the window open and didnt change anything then i opened my browser went to minecraft.net and tried to log in then i typed my answers it worked then i swicthed to launcher windows and pressed the button again and it worked.
I can't reproduce this. Is this still an ongoing issue for you?