Urgent! Server help!

I have posted tons of threads about this but none of them will have this much information.
I need help urgently, my server keeps crashing and I cannot stop it.
The story: I found out the the bukkit staff had uploaded the beta build of 1.5.2 craftbukkit. So I added that and then updated 2 plugins got suddenly for updated. Which are WorldEdit and SuperSpleef.
Right after that, the crashes have been coming nonstop. My crash files doubles these past 2 days.

Now everyone wants info right?
First of all I'd like to say that everytime a certain player joins that's when the server crashes and times out.

Now here's the crash error file: http://pastebin.com/dBHdGVZm
Here's the Start-Up log: http://pastebin.com/8Zz6nWE1
Here's the crash that shows up int he console: http://pastebin.com/bjc2fA8C

I recently updated NoCheatPlus.

My plugins:
AntiInvisibility 0.9
Buycraft 5.3
EchoPet 1.5
Essentials 2.10.1
EssentialsChat 2.10.1
EssentialsGroupManager 2.10.1
EssentialsSpawn 2.10.1
MCMA_Compat R22A
Multiverse Core 2.4 AB
Multiverse Inventories 2.5 B335
NoCheatPlus 3.9.1 RC B.509
NoSpawnEggs2 2.0.2
Plotme 13.0
PSA 1.0
SkyBlock Co-Op 1.5.1
SpamTrap 0.2.0
Spleef 0.1.7
SurvivalGames B 0.4.11
Votifier 1.9
War 1.7.4
WitherManagement 1.1
WorldEdit 5.5.6
WorldGuard 5.7.3

Please help me. I'm in urgent need.

Here's the error it shows

 

I had the exact same thing. I looked through my startup log, and saw many errors when each plugin was booting up, and went through updating each of those plugins, then it worked. Try that...

 

I have updated everything, it's still happening please help me.
I can't do this, it's been happening nonstop for 3 days.

Tagging BukkitStaff np98765
TnT mbaxter c0mp
Please, I have no clue what is happening.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Restart the server, if it doesnt work, take out all your plugins put it in a safe folder, start up the server, if it doesn't work, I really don't know :i

 

Like it happens when someone signs in, then it gives me a Ticking Entity and java.lang outofbounds something like that. As if a part of my world was corrupted or something :I

 

Oh, Uhh i'll try to think of something ;]

 

Thank you so much. Right now the server is at 1.5.1 and it has no problems.
I'll be posted on this thread, I need a solution urgently :/

Is anyone out there that can help me at this time?

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

Still can't think of anything at the moment =/= sorry

 

I have had this problem with my server. I took out all the plugins one by one. The found out it was Group Manager. It was a YAML error but then it happened again for no apparent reason. I took the plugin out loaded the server. Shut it down. Then loaded it up with group manager and it worked.

 

I'm gonna try that right now, hopefully it works.

 

2013-05-05 14:05:58 [SEVERE] Error occurred while enabling EchoPet v1.5 (Is it up to date?)
This plugin should get fixed.

 

I have disabled the plugin and even updated it to a BETA version, yet it still happens :I

I tried what you did, still doesn't work. :I

Bumping for help, I still have this problem.

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

InspectorFacepalm had mentioned removing all plugins, as did falcon2_0. Have you tried that? I've seen those Ticking Entity errors when there's a plugin doing something naughty. Narrowing it down to *which* plugin would be your first step.