Bug/Issue Co-op game crashes for host when friend joins.

I am brand new to Stardew.

I have a save that has around 5 hours play time on a multiplayer farm with a friend. (it was in one session, my first farm). My friend and I wanted to continue it. I can join the farm (as the host) fine. But when my friend joins it crashes the game for me. Not for them though.

I had a little look online and saw that being in their house when they spawn is a fix. That didn't work. Nor did moving furniture out. Which I also saw was a fix.
I have yet to to try a new farm to see if the issue is over all of them though. So i'm not sure if it's this save specifically or a wider issue.

We'd like to carry on this farm as we had a good amount of time invested in it too.

So if anybody could give me any help or a fix i'd be much appreciated.