it wont let me change profile pic

Try clearing your Cache and then, after you upload your photo, press CTRL + F5 (Refresh) and it should work.

clear your cache
or make sure you have the correct image size (100x100 is recommended)

I have the same button, I clear the cache, even if its 100x100 it still takes a while to change, it will let me change it, but it takes a whie constantly doing the same thing, if thats the problem ,then go to settings, change your ava even if its not completely there, then exit the tab, go back, and it should be there, if not, repeat, it usually takes me two time