This bug has now been fixed in Patch 1.19.31
The existing borked relationships will not be auto-fixed.
Use the methods described here: http://sims4.crinrict.com/en/2016/06/sim-is-suddenly-married-to-an-unknown-sim/ to fix your trees.
So I opened up my game this morning and I was inviting a female sim (named Ellie) over to my house... I noticed when Ellie's relationship panel popped up that she was married to someone named "Mirabel Woodworth." Here's the catch: Mirabel Woodworth is not a sim in my town or my library. Better yet, Ellie was already married to a male sim (Jake) whom she lives with. I entered Jake and Ellie's household and the Ellie, who is supposedly now married to Mirabel Woodworth, doesn't even know a sim by the name Mirabel Woodworth!!! Mirabel Woodworth is nowhere in her relationship panel. She thinks she's still married to the Jake and they maintain all romantic interactions, but my family tree says she's married to Mirabel. If I click on Jake's side of the family tree, he says he's still married to Ellie. This is going to drive me insane and I can't even invite Mirabel Woodworth to my lot to divorce her because my sim doesn't know her!! I don't use mods or anything third party. I want to fix this very badly but I also don't want to corrupt my game, as it is my legacy file. Please help me ☹️
@Salee7 merged with an existing thread about this. See the solution on how to fix the issue.
