Was exploring underwater.  Had already found one chest near same location and had no problem.  Found specific chest and the server crashed when I tried to open it.  Restarted server, tried to open chest again, and again it crashed.  Restarted server, tried to break chest, and again chest crashed.  

Seed: [3089412]

Near -395 50 290

Since other chest open fine I'd assume that there is an item in the chest causing the problem.