Ive been trying to change it all day. When I click on 'upload new avatar' it just tells me to provide a valid email address which I have. Does anyone know why this is happening?

you should put in a ? help ticket ^^^ up there

i know they have been doing updating today -- maybe that's it?

What's a help ticket? Yeah I noticed the site was being updated earlier I will try again tomorrow. Thanks. 

click on it up there on the purple banner -- it's how you can contact support to ask your question

I was having the same problem and same error message.  Finally clicked top button above the upload new avatar to find image then click upload new avatar and it worked.

Just tried again and it said "avatar saved" but it's not changed lol I give up!

I guess mine worked because I didn't have an avatar.  I just tried to change the avatar I have now by clicking Select Image and then clicking Change Avatar and nothing happened.  I cannot change mine now either.  I guess they are still working out some of the bugs :(