Uploading images on marketplace management tool freezing

I have been having trouble uploading images with the marketplace management tool. When I upload any number of images, it always stops on the last image and won't finish or let me save or close the popup. After letting it sit for a while I can usually reload the whole page and all the images will have uploaded, but it shouldn't get hung up in the first place. This is using Firefox 70.0.1 64 bit on Windows 7 without any browser addons.

Hello Jeff M., Please carefully work through to the first three steps of our guide to Solving Technical Issues : Step 1: Make sure to use the right browser . Please check if these issues persist when using both Chrome and Firefox.  Step 2: Ensure that there are no extensions/addons interfering with Roll20. Please disable all add-ons/extensions. It sounds like you've checked addons. Step 3: Clear your cache.   If none of the above succeeds, please thoroughly work through  Step 4 . (Don't forget the complete Console Log!) Thank you! 

sure thing