I think it's the loading screen just before the start of the wedding event (and you pick your outfit?) Everything before that works fine. Loaded previous saves, made new hard saves. Went back and forth like that a couple of times. It did not work. Any more I can do?
#Stuck on loading screen at my own wedding
opal moth
opaque canyon
The easiest way around this bug is to be outside the town hall when it starts and you'll be teleported in without the bug
tawny vault
Hey, yeah I've been getting the same thing too
opaque canyon
Hey, yeah I've been getting the same thing too
Did you try the workaround?