The client is crashing every minute or so since updating my server to 14w30b. The server itself isn't crashing and others on my server are also reporting crashing, but only every once in awhile. On my system it is every minute or so. The client said it could not send my crash report to mojang because it thinks my client is modded, which it is not. I'm not doing anything special in the game to make it crash and it is happening no matter the situation or items used.

Here is the copy/paste crash report:

---- Minecraft Crash Report ----
// I feel sad now

Time: 7/23/14 9:35 PM
Description: Tesselating block model

java.lang.IndexOutOfBoundsException: Index: 1, Size: 0
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at csu.b(SourceFile:88)
at chc.a(SourceFile:156)
at cjs.a(SourceFile:254)
at cjs.b(SourceFile:105)
at cjs.a(SourceFile:45)
at cjs.a(SourceFile:35)
at cjq.a(SourceFile:62)
at cmt.b(SourceFile:156)
at cmm.a(SourceFile:71)
at cmm.run(SourceFile:31)
at java.lang.Thread.run(Unknown Source)

A detailed walkthrough of the error, its code path and all known details is as follows:
---------------------------------------------------------------------------------------

– Head –
Stacktrace:
at java.util.ArrayList.rangeCheck(Unknown Source)
at java.util.ArrayList.get(Unknown Source)
at csu.b(SourceFile:88)
at chc.a(SourceFile:156)
at cjs.a(SourceFile:254)
at cjs.b(SourceFile:105)

– Block model being tesselated –
Details:
Block: minecraft:gravel
Block location: World: (-160,35,146), Chunk: (at 0,2,2 in -10,9; contains blocks -160,0,144 to -145,255,159), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Using AO: false
Stacktrace:
at cjs.a(SourceFile:45)
at cjs.a(SourceFile:35)

– Block being tesselated –
Details:
Block type: ID #13 (tile.gravel // avl)
Block data value: 0 / 0x0 / 0b0000
Block location: World: (-160,35,146), Chunk: (at 0,2,2 in -10,9; contains blocks -160,0,144 to -145,255,159), Region: (-1,0; contains chunks -32,0 to -1,31, blocks -512,0,0 to -1,255,511)
Stacktrace:
at cjq.a(SourceFile:62)
at cmt.b(SourceFile:156)
at cmm.a(SourceFile:71)
at cmm.run(SourceFile:31)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 14w30b
Operating System: Windows 8.1 (x86) version 6.3
Java Version: 1.7.0_65, Oracle Corporation
Java VM Version: Java HotSpot(TM) Client VM (mixed mode, sharing), Oracle Corporation
Memory: 129958928 bytes (123 MB) / 237498368 bytes (226 MB) up to 518979584 bytes (494 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M
IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95