on minecraft load screen it says"failed to sync user data"

Try power cycling your Xbox first. Press and hold the power button on the front of the console for several seconds until the Xbox shuts completely off. Unplug the Xbox power cord from the back of the console for 1-2 minutes. Plug it back in and turn it
on. I usually reset my router at the same time for a fresh reset of the system. Once everything has reset, try logging back into your game.

Best wishes,

Cowgirl

Yea i just tried that it did the same thing

In my house I have two xbox so I loaded up minecraft on the second one (not mine) and minecraft loaded perfectly normally. After closing down minecraft properly (returning to the main menu and the quitting) I attempted to load up minecraft yet continued
to have the same problem. Thank you for your help so far.

Thank you for taking the time to post this on the Xbox Forums. We understand that you are currently experiencing difficulties with syncing your save data.

Did you happen to launch this game on a different console the last time you were able to sync your save data successfully? Its possible that you may not have closed the game correctly, thus prevent your save data to sync so that you can use it on another
console.

If this is the case, you would have to go back to that console and you have to close the game there and then you should be able to let you use your save data elsewhere [you could launch the game once more on that other console and let the save data sync
if it needs to, then close just as a precaution].

Perhaps you could attempt to connect to an alternate network on your console to see if this allows you to sync your save data, such as a mobile hotspot.

There is an article that covers
Xbox One game saves to the cloud error messages that may be of some use to you.

Give this a try and let us know if this works for you.

Hi and thanks for reaching Microsoft Xbox gamer's community. My name is Josef.

I'm an Independent Advisor and a Microsoft Xbox user like you.

Hope you're doing great today despite this Player1001

I also saw some players reporting something similar since the last October Minecraft update.

If even the world doesn't load after reinstalling Minecraft the best option is start to report this problem to Mojang from here:

https://bugs.mojang.com/