I didnt work for me either. I will try. 1.21.101 but the anticipated 1.21.100 fix did not fix my world loading or the Xbox cloud issue at all. I even deleted the game saves from my Xbox to force the system to download my cloud saves again and got excited when I saw my Xbox running a huge download that took about 10 minutes on a very high speed connection (my game inflated from 1.4 to over 2 GB during this fiasco) but I was finally disappointed by the “Cloud Save Failed” coming up again after all the time spent with Mojang support and the promised fix I waited for.

reddit thread many others having this issue:
https://www.reddit.com/r/Minecraft/comments/1kme3sr/thread_for_cloud_sync_failure_large_world/

I didnt work for me either. I will try. 1.21.101 but the anticipated 1.21.100 fix did not fix my world loading or the Xbox cloud issue at all. I even deleted the game saves from my Xbox to force the system to download my cloud saves again and got excited when I saw my Xbox running a huge download that took about 10 minutes on a very high speed connection (my game inflated from 1.4 to over 2 GB during this fiasco) but I was finally disappointed by the “Cloud Save Failed” coming up again after all the time spent with Mojang support and the promised fix I waited for.

I didnt work for me either. I will try. 1.21.101 but the anticipated 1.21.100 fix did not fix my world loading or the Xbox cloud issue at all. I even deleted the game saves from my Xbox to force the system to download my cloud saves again and got excited when I saw my Xbox running a huge download that took about 10 minutes on a very high speed connection (my game inflated from 1.4 to over 2 GB during this fiasco) but I was finally disappointed by the “Cloud Save Failed” coming up again after all the time spent with Mojang support and the promised fix I waited for.

@Levi Klopfenstein I did open a support ticket back in May and had the same thing happened, it is not unusual that they won't ever confirm anything more they to say something along the lines of ‘they acknowledge, do not have an estimated date or time as to when the fix for the Cloud Sync Failed issue will be released to players. They did assure, however, that the development team is aware of what is occurring and indeed are working on a fix.’ Like @Shane Cardwell mentioned we are waiting for this to be hopefully addressed in 1.21.100 (fingers crossed)

Levi Klopfenstein, are you looking at the change log for Minecraft Beta & Preview - 1.21.100.20 ?
https://feedback.minecraft.net/hc/en-us/articles/37264366737421-Minecraft-Beta-Preview-1-21-100-20

”Stability and Performance

• Fixed an issue where Xbox cloud saves would grow excessively in size with each save. (MCPE-197900)” -
  
  We know the cloud sync error is related to the increase in world size (at least for the many people, tickets and reddit posts I have been involved in along with my own interaction with Minecraft support. And looking at issue ticket 197900 thread, the person who raised the initial ticket they are resolving on 1.21.100.20 specifically uploaded a screenshot showing the exact same cloud sync error we have been experiencing. I am assuming this hasn’t been released then it won’t be tested yet by anyone without Beta or Preview privileges to tell us if it is or isn’t working since that version has not been released yet.

Yes!!! This is awesome news! Crossing my fingers and updated my Reddit post on r mincraft..

Thank you so much for updating us!

This is a known issue it appears on several tickets and Reddit posts. The largest one I found is 217104 - along with many others who lost worlds we wait support has closed ticket and said they have people working on a fix. It’s nothing you did and like you I have found that lack of storage is not an issue it’s something else causing this.

BTW deleting your worlds in attempt to follow known fixes (at least for me) made it so my game went from unable to save only to unable to play because the game tries to download from the cloud and it fails. So think twice before deleting your worlds. They may still live happily on your Xbox for now. I tried other devices also to restore the world save, no fix.

several posts on reddit about this same issue. known issue, support ticket acknowledged but no fix yet or “official' bug confirmation of issue but they know about it.

7 year old world, same issue on XBSX. Strangely the size of my world DOUBLED when this started to happen. I am under the same impression this is a more widespread issue, the support ticket I opened and finally responded to indicated they are aware of it and working on a fix… no ETA… yada yada.. check Minecraft news for updates and then closed ticket. Hope I’ll get my world back this sucks! I did download my save like others have said using tools on the Xbox but as we are seeing this workaround appears to be temporary (for now). If someone makes a tool to fix these worlds they can make money probably I would pay someone to fix mine its worth it to me!