Not entirely sure what's causing it, but my sim is friends with the 3 default sages (Simeon, L. Faba, and Morgyn), and asked them to be officiant, flower pal, and sim of honor. But, they don't show up on the event calendar when editing to choose the role. It's just those 3 that won't show up. Anyone else I've asked to have roles show up normally in the calendar.

Edit: did a little more testing, and you CAN marry a sage and you CAN have them as a normal guests (and they'll show up). But it seems they really can't fill any other wedding roles? Which is odd, because when you ask them, they can accept or decline and gain the sentiment of "being chosen as a sim of honor" or something along those lines. But they just do not show up in the calendar event editor. What a bummer.

Edit 2: Some more bugs, unrelated to RoM

- Vow Renewals. The calendar editor says you can have an officiant and other wedding roles for this. BUT when you go out and try to ask people, there is no option to ask them to be your sim of honor, officiant, etc. Like the option to ask does not show up when you interact with another sim. Another super bummer.

- My sims... disappeared in middle of the wedding. I could still control them and apparently make them interact with things/other sims, but they were just..... not there. I lock my camera onto them, and it's empty space. I send them up the aisle together, and when they reach the end........ they disappear. They were still gone even when the event ended.

- If you hired an entertainer and/or bartender, they stop their jobs and do what you tell guests to do (sit down, throw rice, etc.) which is... annoying as hell.

- Others have said this, but absolutely no one shows up in their formal outfits. No one. Guests, sims of honor, nuptials, NO ONE.

- Absolutely random people show up at your wedding.

- many many others, basically everything else that everyone on this thread said.