Scoreboard objectives with stats are removing after relogin into world

Cannot reproduce, works fine for me.

This might only happen with worlds that were updated to the snapshot, which is a serious issue. Update the description to affecting pre snapshot worlds and reopen the issue. I have one world (update 1.12.2) with a few dummy objectives and another objective that used the play_one_minute stat. Upon updating the world to 18w03b, the dummy objectives remained and the play_one_minute objective was removed as expected (because the play_one_minute stat was changed). After updating the world, creating new objectives and/or deleting old ones works, but exiting and reentering the world resets these changes, replacing the removed objectives and deleting the newly created ones. Objectives work just fine in a world that was created when using the snapshot.

For example/clarification say that pre snapshot I had objectives a, b, and c all of type dummy. Update to the snapshot, do /scoreboard objectives list; objectives a, b, and c show up. Now, delete objective b and add objectives d and e, both of type dummy. Do /scoreboard objectives list and objectives a, c, d, and e show up. Exit the world and reenter, do /scoreboard objectives list again, and objectives a, b, and c should show up. This is the issue the op was experiencing.

See MC-123011.