Help overlay error!

Whenever I want to upload an overlay It sorta crashes but not really, I can’t click on anything accept the scroll thing and stuff but it just stops working?
When I picked a random image of a book of the internet it worked just fine and now I got a random overlay of a book
When I wanrt to upload my own image(Mostly it got inverted to a PNG and smaller so that its under 1MB) IT WON’T WORK
It’s like I can’t customize them to their likings cause otherwise it will stop working again?!
please help, I really need the overlays but it won’t give me the ones I want of off internet so I customize them but then it crashes…

if it’s too big, then go to a website that will reduce the image size <3

I did but when I upload it it will do nothing and the only thing i can click are the apps