Ryan Randell

@Zgajak

Hi!

Java was already updated to the latest available version, but I uninstalled and reinstalled it to be safe and there was no change to my issue since it had to do with the included JRE.

I pointed Minecraft to run from my system's java executable and encountered MCL-18306 which required me to delete the JavaCheck.jar file in the game directory for the Minecraft Launcher installation. Post-JavaCheck.jar deletion, the game booted.

This does not solve the initial cause of MCL-21565 which seems to stem from a failed file download. The file JabSwitch.exe does exist in the filesystem under ..\runtime\java-runtime-gamma\windows-x64\java-runtime-gamma\bin, but registers as an empty file with a size of 0B, consistent with @TouchierDwarf125 having a copy of "splashcreen.dll" that is 0B in size.

Relavant Warnings

// [Info: 2022-08-08 19:15:05.2248170: NetQueue.cpp(664)] NetQueue: Starting net action https://piston-data.mojang.com/v1/objects/40b059dfddf5e74e248db4aff2f05dd25e33368e/jabswitch.exe
[Info: 2022-08-08 19:15:05.3194473: LauncherAppRenderer.cpp(289)] MCLauncher.triggerUpdateEvent("coreEvent.downloads");
[Info: 2022-08-08 19:15:34.6209802: NetQueue.cpp(664)] NetQueue: Starting net action https://launchercontent.mojang.com/
[Info: 2022-08-08 19:15:34.7959324: NetQueue.cpp(484)] NetQueue: Primary ip: 2620:1ec:27::cafe:1867, Host: launchercontent.mojang.com
[Info: 2022-08-08 19:15:34.7959932: NetQueue.cpp(573)] NetQueue: Action finished: https://launchercontent.mojang.com/
[Warning: 2022-08-08 19:15:34.7960425: NetQueue.cpp(602)] Action https://launchercontent.mojang.com/ failed in response handler. response code: 404 - error string: '

See also

// [Warning: 2022-08-08 19:20:09.3525045: PistonInstaller.cpp(438)] Download operation for file "'<APPDIR>\Minecraft Launcher\runtime\java-runtime-gamma\windows-x64_staging\869fc0b687986ea26b8ff63c137e03c92234a5c8'" failed with error: FAILED_TO_DOWNLOAD - Operation too slow. Less than 30 bytes/sec transferred the last 60 seconds
[Info: 2022-08-08 19:20:09.3525886: NetQueue.cpp(484)] NetQueue: Primary ip: 2606:2800:11f:1cb7:261b:1f9c:2074:3c, Host: piston-data.mojang.com
[Info: 2022-08-08 19:20:09.3526162: NetQueue.cpp(503)] NetQueue: Action timed out: https://launcher.mojang.com/v1/objects/40b059dfddf5e74e248db4aff2f05dd25e33368e/jabswitch.exe

Please Advise.

Edit: I have reason to believe that the issue is directly correlated to IPV6 issues. After disabling IPV6 on my router, I was able to successfully download the missing file nearly instantaneously, and boot into Minecraft as normal.

Cursory research leads me to believe this may either be a general IPV6 issue, an issue with intel NICs, or a combination of both. Further testing required

I am having the same error, albeit with a different file. 

//Unable to decompress file.
Error details: no such file or directory
Filename on disk: jabswitch.exe
Path: C:\Program Files (x86)\Minecraft Launcher\runtime\java-runtime-gamma\windows-x64\java-runtime-gamma\bin\jabswitch.exe
Exists: File

I have tried all listed solutions above, all versions of the Minecraft Launcher for PC (Win 10/11, Win 7/8, executable and msi installers), Uninstalled/Deleted all relevant files, but still can't get any recourse.

Attached is my launcher log.

They did disappear however after I posted this without my help.