I tried to upload an image within the new limits but every time I just get a blank white page and nothing happens.

Hm, I'm working since over 20 years in IT and the only thing you learned very fast is if you upgrade an application to a new version you better do it first in an adequate test system before you start it in the production system because afterwards it could be a desaster/nightmare for all IT Guys and customers.

I'm not very happy with this!