So I updated the SophisticatedCore Mod, restarted the server, went to my inventory to get to a different monitor, server crashed with this crash ↓
crash-log: https://mclo.gs/Hyuw5ud
(debug-log: https://mclo.gs/9mve7le)

Mb it's not bc of your mod, but your package is the only one in the crash log.

Edit:
Just happend again, without being on the server, shutting down the entire server afterwards
crash-log: https://mclo.gs/y2A6U7u
cutted debug-log: https://mclo.gs/QdfLxok

just updated backpacks to latest version and your issue is solved. Please always double check what versions you're using otherwise you will continue to run into issue like htis

Oh, I am really sorry for that, guess I had backpacks still on an older version….