Resolved:• I updated Switch 2 to version 21.0.0 and analyzed the compatibility changes in match version between 18.1.0 and this new version. It generally still works, but in certain cases it doesn’t...
• For example, it’s not possible to update Mario Party Jamboree from:
• S1 fw 18.1.0 → S2 fw 21.0.0 →Error
Edit: Resolved • S1 fw 18.1.0 → S2 fw 21.0.0 →Accepted
• S1 fw 20.5.0 → S2 fw 21.0.0 →Error
• S1 fw 18.1.0 → S1 stock fw 21.0.0 →Accepted
• S1 stock fw 21.0.0 → S2 fw 21.0.0 →Error
S2 on fw 20.5.0 did accept the update from S1 fw 18.1.0.
• Another example:
• Iron Meat on S2 fw 21.0.0 requires a mandatory update
• But on S1 stock fw 21.0.0, the program can be opened
• Sending the update from S1 fw 18.1.0 → S2 fw 21.0.0 →Accepted
• Variation transfer →Accepted
•Mario Galaxy 1+2:
• S1 fw 18.1.0 → update to S2 with 21.0.0 →Accepted
• S2 → update to S1 stock with 21.0.0 →Accepted
• S1 stock with 21.0.0 → S2 with 21.0.0 →Error
Edit:Danger: Update S1 on S2 corrupts data, game crashes; this didn't happen on S2 fw 20.5.0
• Mario Party Jamboree, local update on Switch 2 → requires mandatory update
• S1 fw 18.1.0 → S2 fw 21.0.0 →
Accepted• The game launches on Switch 2 and works perfectly.

Error
Danger: Update S1 on S2 corrupts data, game crashes; this didn't happen on S2 fw 20.5.0












