Unfortunately I already found one that I cannot fix on my side.
@thegamemaster1234, ItemCustomizer gives me this error and completely breaks my modData syncing between client and server. Even in Single Player when SSC is enabled for it.
Code:
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object.
at ItemCustomizer.UIPlayer.Save()
at Terraria.ModLoader.IO.PlayerIO.SaveModData(Player player)
I suspect it does that since there is no data to save. Should at least
return new TagCompound(); if there is no data.