Server crashed, can't connect anymore.

[xEdog 0]

I created a Minecraft 1.16.1 server, using the Valhelsia 3 Server modpack, and it runs from my PCs ssd (We all deleted the KubeJS mod because it conflicts with some of the Mekanism and Immersive Engineering crafting recipes). It has been pretty stable since, but just recently crashed because a single tick took 60.0s, where maximum is 0.05s. Everytime my friends and I try and join now, it gives me this error, "failed to synchronize registry data from server, closing connection". The Forge versions for the server and user version are the same, aswell as the mod versions. Any information that I can provide to help anyone with my solution I can provide. Full crash report is attached. 

crash-2020-09-15_19.54.19-server.txt

[diesieben07 7366]

So does it start up again now? If so: Post a new debug.log from server and client.