[11:07:28] [main/WARN]: Error loading class: eu/vanish/commands/VanishCommand (java.lang.ClassNotFoundException: eu/vanish/commands/VanishCommand)
[11:07:28] [main/WARN]: @mixin target eu.vanish.commands.VanishCommand was not found d4f.mixins.json:VanishCommandMixin from mod d4f
[11:07:28] [main/WARN]: Error loading class: net/minecraft/class_5513$class_5837 (java.lang.ClassNotFoundException: net/minecraft/class_5513$class_5837)

@Reimnop

You can ignore those, they only exist for Vanish compatibility.