Advancement counter can desynchronize and double-count completed advancements

[ndg-creative]

My kid and I are playing with the AchieveToDo mod on LAN. He played for a little bit without me and got 5 advancements that I wasn't there for. In the past, I have simply gotten those advancements when I logged in again, and we stayed even in our number of advancements. When I logged back in to the game just now, it spawned me in at our world spawn instead of where I was when I logged off, and suddenly gave me 300+ advancements that I didn't earn.

Super disappointing as we're not sure how to roll that back, and I now have skills he doesn't have, and a bunch of things I didn't earn.

Oddly, the un-earned advancements don't show up in the advancements tabs, but the unlocked rewards do show up in the AchieveToDo tab? (attaching screenshots).

[ndg-creative]

On further exploration, it looks like it might have given me all the advancements we already had again, and counted them as new advancements. I'm wondering if there is a way to change the number of advancements I have in the game files somewhere? That should remove the rewards, and get us back to where we were?

[diskria]

Hi! Thanks for the detailed report.

First, I want to clarify one thing because I might have misunderstood your description. You mentioned that the game suddenly gave you 300+ advancements, but later you wrote that the un-earned advancements do not appear in the advancement tabs. Because of that, I'm not entirely sure whether the advancements were actually granted or if the advancement counter simply increased incorrectly.

From what you described (especially the part where you were spawned at world spawn instead of your logout location), my guess is that something unusual happened with the player session or server shutdown. For example, if the host closed the world abruptly while another player was still connected, the game might not have saved the player state correctly. That can sometimes lead to desynchronization issues.

Another possibility is that the datapack treated you as a different player instance (for example if your UUID changed for some reason). In that case the cooperative advancement system may have re-granted all already completed advancements again, effectively doubling the advancement count.

Based on the numbers you mentioned (295 vs 590), it really looks like the system simply counted the same advancements twice.

Important thing to know:
The abilities and unlocks in the AchieveToDo tab are tied to the advancement counter stored in the scoreboard (the yellow number shown on the right side of the screen). The mod unlocks abilities based on that datapack's counter value.

So if the scoreboard value becomes incorrect, the mod will unlock abilities as if you had legitimately earned that many advancements — even if the advancements themselves were not actually completed.

Before fixing anything, it would be helpful to check whether the advancements were truly granted or if only the counter is wrong.

You can verify this by opening:

Advancements > BlazeandCave's Advancements Pack > Advancement Legend

There you can see the actual number of advancements completed by the player. This value reflects the real advancements stored by Minecraft itself.

If that number is correct but the scoreboard value is higher, then it's simply a desynchronization between the real advancement count and the datapack counter.

In that case the fix is easy: you just need to reset the scoreboard value to match the real number of completed advancements.

You can do this with the following command to set your counter back to 295:

/scoreboard players set ndg-creative bac_advancements 295

That should immediately restore the correct unlock state and remove the unlocked abilities.

Since the advancement UI itself does not show the extra advancements, this strongly suggests that the advancements themselves were not actually granted, only the datapack counter got incremented again.

Also,

Unfortunately, items, experience, and trophies that were already granted as rewards cannot be rolled back automatically, as far as I know.
Minecraft does not provide a built-in way to revert those rewards once they have been given, so they would need to be removed manually if you want to fully restore the previous state.

[ndg-creative]

This worked - thank you so much for the speedy reply! No idea what happened, but it was just a glitch where it re-awarded me all the same advancements again. :)

[diskria]

Okay, I'll leave this open so others can quickly find a solution to this problem.
Also, I'll try to fix this in the future. I think I could control this counter from the mod's side so that it wouldn't allow such desynchronization.

[JayJaden]

Just chiming in to say that I also had this issue a few weeks ago. I was hosting a LAN world, and after my friend disconnected and quickly reconnected again, the same thing happened to us as well. I don't know if the quick reconnect had anything to do with it but maybe it helps in finding the problem.

Thank you for providing the solution to update the scoreboard with the command though, thatll be nice if it happens again in the future. I had to spend an hour or two digging through the nbt files and manually fixing the state of the advancements haha