[MCL-15410] 1.16.4-pre1 does not show up in the Launcher / version manifest cannot be parsed

1.16.4-pre1 doesn't show up in the launcher for some users.
Launcher log

Here's the launcher log, there are lots of error messages after line 50.
launcher_log.txt
[Info: 2020-10-15 14:28:18.6752509: GameVersionManager.cpp(210)] Got available versions manifest from https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z
[Error: 2020-10-15 14:28:18.6972580: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[0].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6974563: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[0].sha1: Unknown key
[Error: 2020-10-15 14:28:18.6975895: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[100].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6976955: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[100].sha1: Unknown key
[Error: 2020-10-15 14:28:18.6977669: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[101].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6978345: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[101].sha1: Unknown key
[Error: 2020-10-15 14:28:18.6979004: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[102].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6979658: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[102].sha1: Unknown key
[Error: 2020-10-15 14:28:18.6980354: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[103].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6981197: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[103].sha1: Unknown key
[Error: 2020-10-15 14:28:18.6981865: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[104].complianceLevel: Unknown key
[Error: 2020-10-15 14:28:18.6982517: GameVersionManager.cpp(216)] https://launchermeta.mojang.com/mc/game/version_manifest.json?_t=2020-10-15T14:28:18Z.versions[104].sha1: Unknown key
[...]