Can you upload a save from that game, preferably before discovering Liberalism?The trigger for the first Protestant UHV is bugged.
I aim for this victory in my actual vikings game. Researched Liberalism in 1400 AD and took Printing Press for free, founding Protestantism.
I am absolutely sure no other civ has researched Economics or Constitution (checked per WB).
Could it be a problem that I researched Liberalism before becoming Protestant?

in the city for every Open Border agreement you sign.

The game does not crash to desktop or present any failure message. Just continues its turn forever. Tried three times, always the same procedure. The save game is exactly before the turns end.