Scoreboard fails to save after crash

My Minecraft was force-quited for system matter, leaving World/data/scoreboard.dat containing `1F 8B 08 00 00 00 00 00 00 00`. When I reenter the map, the scoreboard is totally reset. That's nothing wrong.

 

However, when I add an objective in the game and S&Q, the scoreboard.dat remains unchanged, and reenter the map there's still no scoreboard