[14:14:00] [Server thread/INFO]: User issued server command: /pet spider
[14:14:00] [Server thread/ERROR]: "Silently" catching entity tracking error.

and

[14:14:44] [Server thread/INFO]: User issued server command: /pet wolf
[14:14:44] [Server thread/ERROR]: Could not pass event CreatureSpawnEvent to SafeCreeper v1.5.2.5
org.bukkit.event.EventException

details
http://pastebin.com/BvbNaC19

Resolved.
bd7bc37
9688fae