Can't "press" edit button!? Help!

When I upload a photo/image either in Media or for a post/page usually I can press “edit” and I’m able to scale the image. I cannot do that now for some reason, since yesterday. I’ve never had this problem before. I logged out of wordpress, I even cleared my cache and cookies, but still nothing is working. I need to change an icon asap, but I can’t put it on my site because it’s too large as is. Help! What could be causing this??