Quick answer: Unreal SaveGame from version N+1 failing to load on version N? Forward-version saves can't be loaded by older code - detect and refuse gracefully.
Player on beta branch saved a game. Rolled back to stable; save shows as corrupt.
Version-gate loads
if (SaveVersion > CurrentSaveVersion) {
ShowError("This save was created in a newer version");
return;
}Friendly error; doesn't corrupt the save by partial-loading.
Backup saves per version
Saves keyed by version. Each version is read-only by its own version; new versions migrate forward.
Document the policy
Players read 'newer save = different branch'. Trust restored.
“Save format evolution is forward-compatible at best. Backward is not free.”
Document the save version policy for players. Reduces support; sets expectations.