BadFluff

So what image types can I upload as jpgs aren't working?

I recently installed skyrim SE and a bunch of mods. Everything is great except this weird glow around objects. Any idea how to fix this? Just got back in to PC gaming from an 8 year break and am rusty. I am afraid I'm missing something simple but just lost right now. Help please? Also, I am trying to put in a screenshot but it keeps saying file extension is wrong....