Bukkit

PLEASE FILL OUT ALL THE INFORMATION BELOW! IF YOU DON'T DON'T EXPECT IT TO GET FIXED!

What steps will reproduce the problem?
Player logs out (file is written to the disc) and back in, data gets cleared on restart.

What is the expected output? What do you see instead?
All books and player heads get cleared on the player logging out and back in.

Have you tried the latest version of MultiInv from http://build.yu8.me:8080/job/MultiInv3/ (If not please try it to see if it solves your issues)?
I haven't tried it because of the 1.9 update, i wasn't sure if it would work or not.

You can either fill out the information below or use the plugin DebugReport to generate a report:
http://dev.bukkit.org/bukkit-plugins/debugreport/
Download and install, then wait for the error to occur. Once it has do the command /multiinv report to generate a complete report.
The report file will be in the DebugReport folder.

What version of the product are you using (if you say "latest" you will NOT be helped)?
v3.3.5

Do you have an error log of what happened?
This is the errors i'm getting for books and skulls on the players logging off with them in their inventory or enderchests - http://pastebin.com/sEn6Sr5J

What are your world folder names (with proper capitalization)?
HollowCraft, Oceanworld2.0

What is the contents of your config.yml and groups.yml?
http://pastebin.com/VJiGkfLD

What is the entire list of plugins on your server (doing /plugins on the console and pasting the output is a quick method to do this)?
26.03 15:29:48 [Server] INFO Plugins (45): AsyncWorldEditInjector, CoreProtect, WorldEdit, EasterEggHunt, TerrainControl, Essentials, ClearLag, TuxTwoLib, Chairs, WorldBorder, Votifier, ProtocolLib, WorldGuard, BungeePortals, KitAdder, AsyncWorldEdit, EchoPet, PermissionsEx, JailWorker, mcMMO, GAListener, Vault, GriefPrevention, EssentialsSpawn, EnjinMinecraftPlugin, AreaShop, MultiInv, PlaceholderAPI, EZRanksLite, MarriageMaster, RandomTP, Auctions, SignShop, WarpPortals, SilkSpawners, Brewery, Citizens, eTokens, MobCatcher, GPRealEstate, PhatLoots, VentureChat, Denizen, CompatNoCheatPlus, NoCheatPlus