THE SUMMARY IS THE DESCRIBTION BUT THIS IS THE CRASH REPORT

---- Minecraft Crash Report ----
// My bad.

Time: 04/12/15 12:29 م
Description: Ticking entity

java.lang.NullPointerException: Ticking entity
at aaa.a(SourceFile:44)
at zu.m(SourceFile:117)
at ahn.a(SourceFile:1467)
at lp.a(SourceFile:719)
at ahn.g(SourceFile:1445)
at ahn.k(SourceFile:1335)
at lp.k(SourceFile:552)
at net.minecraft.server.MinecraftServer.D(SourceFile:625)
at net.minecraft.server.MinecraftServer.C(SourceFile:553)
at bxz.C(SourceFile:154)
at net.minecraft.server.MinecraftServer.run(SourceFile:457)
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 aaa.a(SourceFile:44)
at zu.m(SourceFile:117)
at ahn.a(SourceFile:1467)
at lp.a(SourceFile:719)
at ahn.g(SourceFile:1445)

– Entity being ticked –
Details:
Entity Type: SmallFireball (aaa)
Entity ID: 352
Entity Name: Small Fireball
Entity's Exact location: 184.50, 65.90, 106.59
Entity's Block location: World: (184,65,106), Chunk: (at 8,4,10 in 11,6; contains blocks 176,0,96 to 191,255,111), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Entity's Momentum: -0.18, -0.01, -0.03
Entity's Passengers: []
Entity's Vehicle: ~_ERROR~ NullPointerException: null
Stacktrace:
at ahn.k(SourceFile:1335)
at lp.k(SourceFile:552)

– Affected level –
Details:
Level name: my world
All players: 1 total; [lr['adhamZ18'/278, l='my world', x=168.59, y=64.00, z=107.30]]
Chunk stats: ServerChunkCache: 290 Drop: 0
Level seed: -5716831465969675212
Level generator: ID 00 - default, ver 1. Features enabled: false
Level generator options:
Level spawn location: World: (0,0,0), Chunk: (at 0,0,0 in 0,0; contains blocks 0,0,0 to 15,255,15), Region: (0,0; contains chunks 0,0 to 31,31, blocks 0,0,0 to 511,255,511)
Level time: 0 game time, 0 day time
Level dimension: 0
Level storage version: 0x00000 - Unknown?
Level weather: Rain time: 0 (now: false), thunder time: 0 (now: false)
Level game mode: ~_ERROR~ NullPointerException: null
Stacktrace:
at net.minecraft.server.MinecraftServer.D(SourceFile:625)
at net.minecraft.server.MinecraftServer.C(SourceFile:553)
at bxz.C(SourceFile:154)
at net.minecraft.server.MinecraftServer.run(SourceFile:457)
at java.lang.Thread.run(Unknown Source)

– System Details –
Details:
Minecraft Version: 15w49b
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.8.0_66, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 79381080 bytes (75 MB) / 281186304 bytes (268 MB) up to 1060372480 bytes (1011 MB)
JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
IntCache: cache: 0, tcache: 0, allocated: 12, tallocated: 94
Profiler Position: N/A (disabled)
Player Count: 1 / 8; [lr['adhamZ18'/278, l='my world', x=168.59, y=64.00, z=107.30]]
Type: Integrated Server (map_client.txt)
Is Modded: Probably not. Jar signature remains and both client + server brands are untouched.