http://pastebin.com/iFPVmn5a

Also having this issue. Will crash servers. http://pastebin.com/VLEfEkTu

EDIT 1: On the server its only on placing. You can break it but it will crash on placing it again.
EDIT 2: After the first crash of placing the fence after the server was rebooted it duplicated the fence to the spot next to it. Then interacting with another double gate near the other one crashed the server with the same crash. After reboot the gate that was interacted with looked like this and duplicated another gate. http://i.imgur.com/yaXbdfn.png (The one connected on one side wasn't there before the reboot.) It seems to only be a rendering issue for the other two as the bounding boxes were in the correct place and interacting with them fixed the orientation.
EDIT 3: The crash happens with Oak gates even though its crashing because of camo. (They also seem to act like camo gates when I assume they shouldn't)
EDIT 4: In edit 2 some stupid kid was messing around with our tests make things confusing. The rendering thing might be something to look into still though.
EDIT 5: This issue seems to effect people on connection also http://pastebin.com/U1rzd6X4

We are having a similar problem.
It looks like a Ghast shot a Fireball on a gate.
https://pastebin.com/GiZqC2wF

Fixed.