Can't upload new images

When I try to upload new images to my library, it just doesn't work anymore. It doesn't do anything and the images never show up later. I've tried changing browsers and clearing my cache and it didn't help. I even deleted a bunch of other images I already had to make room, but that wasn't the problem either. I have no addons in Firefox or Chrome. Windows 10. I think I have Javascript enabled and just basic Windows antivirus/firewall. Feature used to work until suddenly it didn't, weeks ago. I thought it would have been fixed by now.

I thought I included all that information? I think I just figured out the problem, the images are probably too big. A small image just uploaded. Woo for blurry world maps incoming! An in-app notification that the image was too big would have been A+

I had a similar issue recently when I wanted to use several Google Map images I'd combined into a single file as a background and not have it all compressed looking. I use GIMP for image processing (it's free) and by saving as a .jpg instead of a .png there was a large file size reduction. Furthermore, GIMP asks what 'Quality' to use for the .jpg when exporting. If memory serves going from 99% to 98 or 97% saw a reduction of several Mb and got me below the 5Mb limit. Neither the .jpg or 1-2% quality reduction made the map look much different for my purposes.  If that still doesn't work you could use GIMP (or similar) to crop the image into 2-4 chunks, upload them, then in Roll20 position them side by side. That is more work though, I'd start by lowering the 'Quality' 1% first. It'll also eat into your 100Mb storage qutoa quicker.