[Nintendo Switch] Cannot load shared world error

[My Kinda Muffin]

System version 20.5.0 up to date

Grounded version 1.13 up to date

Internet 35.3 Mbps download limited by system

NAT type B

 

Bought Grounded 10/4/25. Played one shared world with a friend for a few days. When I host he lags so he hosts most games. One night I fell asleep while playing. When I logged in the next day I got an error.

 

”Cannot load shared world”

Cannot load a Shared World Backup that is missing the primary save. This world may no longer be shared with you or has been deleted.

 

I made my own new map and hosted it. The next day I had the exact same issue with MY hosted world.

 

I moved the game to play directly from the console instead of the microSD card like I have everything else. No change. 
my friend created a Standard Copy then from that created a Shared Copy and reunited me to it. This worked until my system crashed 15 minutes later and I got the same error again. 

 

I have zero interest in having to go through this process every time I want to play with others. What is the cause? How can I fix this?