I’ve seen only one other person with this issue!
Hopefully someone can help me out!
I reinstalled it and it worked, but as soon as I closed UEFN
and opened it again, got the same issue!
Hey @TheJimmyDodger! Welcome to the forums!
I moved this to the UEFN forums so you’ll get some more input from others possibly experiencing the same issue!
And as far as the issue itself, I’ve had that happen with standard UE in every version. Sometimes you just need to restart the loading process, sometimes you just need to give it time. I’d say 15 minutes should be enough, if it doesn’t move after that it likely froze. Just end the process and reopen it. 
I can’t say that’s the for sure fix, just something I’ve dealt with over years of UE.
I figured it out, no matter how long I would leave it loading, nothing would happen, whenever I get this error, I just keep restarting my PC, usually 2 or 3 times, and it just seemingly works!