I just come back on the server after some time away to find that nearly all my stuff in my chest is gone and that my TARDIS is no where to be seen. I’ve still got my TARDIS remote linked but I don’t seem to be able to summon it. Any help at all? 

  All the TARDIS'S have been wiped when the server updated to U48.7 so you need a new one.

 Aww okay thank you and did the update affect the chests as well?

No if you had stuff in a house it's safe if someone didn't use a hopper on it. Oh and if you had an sonic it is broken it will say 0/0 charge and it won't recharge just so you know.

 If you bought a sonic in the shop before the update then it still works. That's what I'd done and mine still works fine. Also, shop bought ones have unlimited charges. :P

 In my chest tho in my house, I’ve only got 3 items in it where before I left, it was almost full with loads of items like ores, ingots and that. It did have a sign in front of it.

 Did you put 2 signs on the chest because if you only do 1 on a double chest you can still open it on the other half.

 Yeah, I placed like half of the more valuable items like gold, iron and others in the chests in case my TARDIS went missing but I don’t have the items now to help me.