msm doesn't work with latest minecraft 26.1

[dickbalaska]

I've been using msm on ubuntu for ~10 years. This last minecraft update required me to update to java 25.
minecraft still doesn't launch though, it appears to not like something about how you've organized the world folder? The log says:

[23:27:29] [ServerMain/ERROR]: Failed to start the minecraft server
net.minecraft.util.filefix.AbortedFileFixException: net.minecraft.util.filefix.virtualfilesystem.exception.CowFSSymlinkException: Cannot build copy-on-write file system when symlink is present: ./world
at net.minecraft.util.filefix.FileFixerUpper.fix(FileFixerUpper.java:95)
at net.minecraft.util.filefix.FileFixerUpper.fix(FileFixerUpper.java:80)
at net.minecraft.server.Main.main(Main.java:157)
at net.minecraft.bundler.Main.lambda$run$0(Main.java:54)
at java.base/java.lang.Thread.run(Thread.java:1474)
Caused by: net.minecraft.util.filefix.virtualfilesystem.exception.CowFSSymlinkException: Cannot build copy-on-write file system when symlink is present: ./world

[chessmaster8421]

an interim solution, if you only have one world, is to move it from the folder "worldstorage" to world after removing the symlink. It will give an error about not having they symlink, but will start the server

[parsec42]

To get MSM to work with 26.1 you will have to do two things:

move your worlds from worldstorage to the server root and let 26.1 run its migration by calling your server.jar directly with "java -jar server.jar" from the MC servers root directory. Make sure to back your worlds up before doing that.

After that, remove the nether and end folders, otherwise the server will run into a crash loop.