Server: Windows 2012, Java 64 bit 1.8.0_191
Client: Windows 10, Java 64 bit 1.8.0_60
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.
Near -395 50 290
Since other chest open fine I'd assume that there is an item in the chest causing the problem.
MC-126244 '/locate', explorer maps, and treasure maps can cause extreme TPS lag, even leading to a complete server freeze if structure generation is turned off