failed to synchronize registry data from server closing connection. [1.16.4][Server][Modded]

[Veo 0]

Hey, I'm trying to host a modded forge server for me and my friends. We made a custom Modpack per CursedForge.

Everything worked fine until I changed some mods, but nothing I've tried so far helped. Everytime I try to join the server I get the "Failed to synchronize registry data from server closing connection."
 The Server gives me: " [Server thread/INFO] [minecraft/ServerLoginNetHandler]: com.mojang.authlib.GameProfile@34a0dd79[id=17de6071-8fd1-4a9a-bb33-b85e27244f29,name=VeoSpielt,properties={textures=[com.mojang.authlib.properties.Property@26b7a6fb]},legacy=false] (/25.100.177.16:53183) lost connection: Disconnected".

server logs:
latest server log

debug.log
 

[diesieben07 7696]

You need to post the debug.log from client as well.

[Veo 0]

57 minutes ago, diesieben07 said:

You need to post the debug.log from client as well.

oh mb

client log:
latest.log

that's the only log I found here:  

[diesieben07 7696]

The log does not match up with the server log.

The server log shows a login attempt at [10Jan2021 15:03:52.014] . The client log only starts at [16:11:24] (so even different time zones cannot account for this).

The client log also does not show any attempts to connect to any server.

[Veo 0]

1 hour ago, diesieben07 said:

The log does not match up with the server log.

The server log shows a login attempt at [10Jan2021 15:03:52.014] . The client log only starts at [16:11:24] (so even different time zones cannot account for this).

The client log also does not show any attempts to connect to any server.

damn it, sorry. 

server-log

server-debug

client-log

[diesieben07 7696]

Quote

[18:05:03] [Netty Client IO #2/INFO]: Server has additional mods that may be needed on the client: bookshelf@9.3.18, fastleafdecay@v25, dash@1.0.1
[18:05:03] [Netty Client IO #2/INFO]: Client has mods that are missing on server: [clienttweaks, repurposed_structures, mousetweaks, jei, gravestone, ftbguilibrary, jeienchantmentinfo]

From these bookshelf and dash are actually required to be installed on the client. fastleafdecay is most likely a server-only mod.

repurposed_structures and gravesteone are most likely required on the server if you want them to function.

[Veo 0]

Thanks allot, now everything works!
and I learned something too.