Quick answer: Construct 3 Photon multiplayer host's state too large for migration message? Photon caps migration size; compact state.
Host disconnects; migration message exceeds Photon limit; client doesn't get the state.
Compact state
Drop unnecessary fields; compress. Migration fits.
Or migrate in chunks
Per-area state migration; multiple messages. Slower; works.
Pre-compute migration size
Estimate before disconnect; warn if over limit.
“Migration messages have size limits. State design must respect.”
If your game has host migration, the state size is a design constraint. Plan it.