I noticed that when i use the setblock command to place glowstone it appears as a locked chest (purple and black texture). It does not appear as this when i place it myself, and i only appeared as that once I updated my snapshot to 14w10c.
MC-50624
Glowstone placed with the setblock command appears as locked chest.
Resolved
Invalid
0
That's not a "locked chest", that's the "Missing texture".
Probably you've placed a glowstone with data value > 0 - which doesn't exist.