Bedrock at Y=0 level after upgrading to pre-relase version at pre-existing chunks

Did you load this world before snapshot 21w42a?

Please tell us the exact versions in which this world has been loaded.

@violine1101 this is my "main" world so i loaded it in every single version (i mean every snapshot and pre-release) since 1.17 (save is 5-6-year-old)

Thank you for your report!
We're tracking this issue as MC-239878, so this ticket is being resolved and linked as a duplicate.

That ticket has already been resolved as Won't Fix, which means this is considered a bug but won't be fixed. The description of that ticket or the comments might explain the rationale. Please do not leave a comment on the linked ticket.

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