my first guess is that you're not using a good resolution for your cover art?
If this isn't the case, could you give more context about why you can't upload a cover art? maybe a screenshot if an error appear?
Edit: or maybe the issue is that i checked your profile and saw naked ppl, maybe the issue is that you can't (and shouldn't) put this kind of image in a cover art of a game, just in case your game gets recomended for a random kid before being flagged as nsfw...
uhm, why exactly edge doesn't work for you? if you use an outdted OS, PLEASE switch it (i used to have a computer with windows 7 until like some months ago, when i switched it because i couldn't do school homework anymore lol). If is a weak pc, consider upgrade it, i hope $$$ isn't so much of a problem because weak pcs are awful to deal with imo. Like you don't need to pay a whole pc, just upgrde some pieces of hardware
I had a good education and certainly my answer was not meant to offend anyone, but if your only answers are "change PC, money money" then please avoid, not everyone is a child of dads who give away money, the person above only mentioned that it happened to him, PERIOD (I have a lot of respect for people)
All I merely said was this was familiar, so I merely explained what I noticed, tried different ways around the problem and found something that worked. I don't see what other problems have to be focused on, here. :/
