Unable to upload to app store

I am unable to load an app to the app store. I am only using JPG images smaller than the maximum size allowed, but it keeps telling me that JPG, GIF, or PNG files are required. Also, I cannot select a subcategory no matter which category I select, which makes me think there is some sort of JavaScript error on the page that might be causing other errors. Please let me know if you need any additional details. I have attached a screenshot of the errors below:

I tried in chrome and Safari.