When trying to join a modded server, you may get one of the following errors:
- Failed to synchronize registry data from server, closing connection
- Fatally missing registry entries
- Connection closed - mismatched mod channel list
- Incomplete set of tags received from server
This article mainly covers custom modded servers. If you're playing a predefined modpack from our modpacks section, then make sure that you installed the correct version of the modpack from the official launcher used by the modpack. You can find the version of the Modpack and the official launcher in the bottom right of the server section:
In this screenshot, you can see that the server is using version 1.23.1 of the modpack “Stacia Expert” from the CurseForge launcher.
Some launchers like ATLauncher or Prism Launcher allow installing modpacks from different platforms, but especially cracked launchers often keep their own version list which commonly is incompatible with the real modpack.
If you still experience issues with a modpack after verifying that you installed the correct version of the modpack and are using the correct launcher, then please create a support ticket or send us a mail to firstname.lastname@example.org.
One possible cause for these problems is that the server or client are missing mods. You always need to make sure that you have the same mods installed on both sides.
Mismatched mod versions
If you are sure that you installed the same mods, then the issue may be caused by having different versions of these mods installed. Not just the Minecraft version must be the same but also the version of the mods. You can usually find the version of each mod in the file name, e.g., “TConstruct-1.16.5-220.127.116.115.jar” is Tinkers Construct version 18.104.22.1685 for Minecraft 1.16.5.
Mismatched mod loader versions
If the mod versions are correct, then you should check that the mod loader (e.g., Forge or Fabric) version is also the same. You can find the version of your mod loader in the bottom right of the server section:
In this case, you should make sure that you installed Forge version 47.0.35 for 1.20.1 on your client.
It's also possible for these issues to be caused by mod configurations. If none of the solutions mentioned above work for you, then we would recommend deleting the config folder on your PC and server.
To delete the folder on your server, just go to the files section and click the delete button next to the folder with the name “config”.
On your PC, the location of the config folder depends on the launcher you use to install the mods.
The official Minecraft launcher stores its files in the .minecraft folder. This article from the Minecraft Wiki covers where to find that folder: https://minecraft.fandom.com/wiki/.minecraft#Locating_.minecraft
Other launchers like CurseForge or Prism Launcher usually allow you to open the folder by right-clicking on the profile and selecting the open folder option.