Hello!
So it appears there’s some kind of conflict here. So I went into my php.ini settings, set _limits to 512m, flushed caches and CDN. The same thing happens on all my sites on the multisite network that use the Pro Theme.
Before this, I did a manual upgrade. I’m using the child theme for Pro.
Only the Validation and Status pages under Pro are able to load at the moment. All others look like this…

Here’s another screenshot I thought might be pertinent where it says I need to update to the latest version but the installed version is a higher version than the one it is asking to upgrade to. 
Oh also, I did try and disable the plugins under “other plugins” but it didn’t change anything.