I am part of a realm that was currently down in the recent downage. The realm was then brought back up and I noticed that my house had been destroyed. I would like my house to be reinstated if possible.
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You could try contacting the customer support, maybe they can reset the world to a backup, though it might take multiple weeks before you get a response.
Thank you for your report!
We're actually already tracking this issue in MC-161823, so I've resolved and linked this ticket 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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