Today two moderators of mine were unable to tempban anyone, this is one sample log: http://pastebin.com/myveyVx8

apparently the error was caused by a wrong mysql insert query.
moderators were probably in vanish, using vanishnopacket.

thanks

I'm not completely positive about this, but a chat moderator of mine had the same error. He reconnected and it worked, so I'm not sure.

Mine too but this time reconnect didn't work

This only used to happen when the plugin was reloaded, either via /reload or via a plugin manager.

Were either used?

No, i do not use to reload any plugin.

Can I get a list of plugins you have running please?

This might be why it happened on my server, it didn't happen again so far.

GroupManager, NetherRoofProtect, WorldEdit, ChatControl, Vault, BlogMOTD, WorldGuard, Reporter, WelcomeTitle, dynmap, CoreProtect-Anti-Xray, Graves, CoreProtect, BukkitSpeak, Parties, BanManager, ClearLag, DeathMessages, ProtocolLib, HolographicDisplays, BlockNotif, SuperTrails, Essentials, NoCheatPlus, EssentialsProtect, VanishNoPacket, NCore, EssentialsAntiBuild, HomeSpawnPlus, NTheEndAgain, Statistics

Perhaps it's VanishNoPacket, however, the only way this would occur is if it interfered with the PlayerJoinEvent. I've just taken a quick look at the source code for it, but can't see anything obvious.

Using VNP and BM too and banned a couple of players vanished but works well.

Weird.
Unfortunately we can not ask mbaxter in this case because he refuses to support Spigots version of CraftBukkit and Spigot itself for comprehensible reason.

What Spigot version are you running?

Should be fixed in latest developer build