The day before I was on my switch then I get on my computer to use it instead, and I appear at spawn with only a map. I lost all my armor and shulker boxes as well.
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Hopefully you are following the main bug ticket at MCPE-55815, but if possible, would you be willing to share a copy of your world save, so we can try and identify the bug?
If so, perhaps you could add it to MCPE-55815?
On Windows 10 you can use the Export world feature.
On Android or iOS you need to use a file explorer to navigate to Device storage > games > com.mojang > minecraftWorlds
On Xbox or Switch the only way is to upload it to a Realm, and then download the world on Windows 10 or Android/iOS. (Please do not purchase a Realms subscription just to provide a world to us - but if you have a Realm already this may be a viable option if you wish to do so.)
If the world is larger than 10MB you can upload the world to OneDrive or a similar file sharing site, and then share the link (at MCPE-55815)
Thank you for your report!
We're tracking this issue in MCPE-55815, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature to see if the issue has already been mentioned.
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