Not sure if this is the appropriate place place but,

A buddy of mine, NeoFang, was building the city Techland fairly close to my home with my permission. However, protecting the city has been confusing and I found myself locked out of most of my chest. No big problem there, but recently all of my valuable materials vanished. Last time i did inventory i had over 400 diamonds, 600+ iron and 500+ gold. I'm not blaming NeoFang, and I'm sure we can work this out like mature gamers.