MisterD

@peterix so should this be reported elsewhere?

Not sure if this is related, but after deleting the the 21w08b game version, the following message appears in the launcher log:

[Info: 2021-03-17 21:51:00.6921457: GameVersionManager.cpp(488)] Got game version 21w08b manifest from https://launchermeta.mojang.com/v1/packages/194f6e56c8c7548ccb16769b1f0d28a318d0dbf2/21w08b.json
[Error: 2021-03-17 21:51:00.6939493: GameVersionManager.cpp(497)] https://launchermeta.mojang.com/v1/packages/194f6e56c8c7548ccb16769b1f0d28a318d0dbf2/21w08b.json.javaVersion.majorVersion: Expected non-negative integer
[Error: 2021-03-17 21:51:00.6939954: GameVersionManager.cpp(506)] Downloaded invalid manifest

referring to the part of the manifest where it says

"id": "21w08b", "javaVersion": {"component": "jre-legacy", "majorVersion": null}

where null is obviously not a non-negative integer.