Can't load A5 Cathedral Rooftop to finish Part 1

It started happening around Cathedral Rooftop. The client kept crashing when I got close to the ladder in Ruined Square. I had a friend join me in group and give me a portal inside the zone. That allowed me to beat Kitava, but then it crashed right after. Now I can't load cathedral to complete the act.

I've tried loading as a new zone (CTRL-click), I had the same friend give me a portal at the boat to Act 6, I've tried going back from Ruined Square. In all cases, I crash to desktop.

I uninstalled POE (Steam) and reinstalled it, and was able to get past the area that was blocking me. So for others having this issue that is preventing progression, it might be worth a shot.