I'm pretty sure it's deliberate that you can't do anything involving the item server within the Modded Realm, including opening loot chests or using crafting options. You'll have to hop over to the Official Realm if you want to do anything with gear.

As an aside, I'm pretty sure any mods such as Give Weapon and Max Property Rolls that have anything to do with creating or modifying items are done locally and thus not kept when you exit the game.

Thanks, I didn't have any mods on like that. mostly stuff to to improve the ui etc. nothing game breaking or stuff that would give an unfair advantage etc.