Sims Can't Get Married and Error Code

Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Often (50% - 99%)
What is your current game version number? 1.110.265.1030
What expansions, game packs, and stuff packs do you have installed? Get to Work, Get Together, City Living, Cats and Dogs, Seasons, Get Famous, Island Living, Discover University, Snowy Escape, Cottage Living, Growing Together, Horse Ranch, Outdoor Retreat, Spa Day, Dine Out, Vampires, Parenthood, Jungle Adventure, Strangerville, Realm Of Magic, Journey to Batuu, Dream Home Decorator, Luxury Party, Cool Kitchen, Spooky, Movie Hangout, Romantic Garden, Kids Room, Backyard, Vintage Glamour, Bowling Night, Fitness, Toddler, Laundry Day, My First Pet, Moschino, Tiny Living, Nifty Knitting, Paranormal.
Steps: How can we find the bug ourselves? Throw a base game wedding in Sulani on a wedding venue. When you click on the arch the option to get married is greyed out.
What happens when the bug occurs? I tried to get my two sims married but when I click on the arch the option to get married is grayed out. Also, I tried to save my game during the wedding and an error message popped up saying "The game failed to save" along with an error code: 504:9cd940e:84cdf0ce.
What do you expect to see? My sims should be able to get married and I should be able to save my game.
Have you installed any customization with the game, e.g. Custom Content or Mods? Never used.
Did this issue appear after a specific patch or change you made to your system? No

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I was hosting a wedding event in Sulani on a Wedding Venue lot type. Everything was going well until I wanted to start the ceremony. I clicked on the arch and the option to get married was grayed out. So, I moved the arch to a new spot to see if that would fix the issue. But it didn't. Then I replaced it with a new arch, but the option was still grayed out for me. Then I desisted to save my game to try exiting to the main menu and reload my game to see if that would work. But instead, an error code popped up. It took me an hour and a half trying to figure out how to solve this issue and I finally found a way to work around it. I read a bug report here on Answers HQ were someone was having a similar issue as me from four years ago. Minus the error code. I was able to get them married by clicking "get married" in the new relationship category on the pie menu. I didn't even know that option was in there. Then when the wedding ended, I was still unable to save my game and kept getting the error code. I was only able to finally save my game once my married sims traveled to another lot. Also, after the wedding ended a total of 16 "Skillful Sims", "Lifelong Aspirations" and "Always on the Move" Discovery Quest popped up in my notification board.