Why am I getting error trying to change avatar?

[hollyw79]

I'm trying to use a custom avatar- no different than any type of file I've used before.. just a picture of my son.. and it's not letting me. I tried a couple of different times with different pictures and keep getting the same message:

Your submission could not be processed because a security token was missing.

If this occurred unexpectedly, please inform the administrator and describe the action you performed before you received this error.

 

[Wobbles]

The file you are uploading is too big and would need resized before you try again.