Crash when trying to create world

---- Minecraft Crash Report ----
// Hey, that tickles! Hehehe!

Time: 7/22/16 3:59 PM
Description: Updating screen events

java.lang.RuntimeException: Failed to check session lock, aborting
	at azy.i(SourceFile:64)
	at azy.<init>(SourceFile:50)
	at azv.<init>(SourceFile:21)
	at azw.a(SourceFile:83)
	at bcx.a(SourceFile:2108)
	at bic.a(SourceFile:212)
	at bft.a(SourceFile:346)
	at bic.a(SourceFile:352)
	at bft.k(SourceFile:409)
	at bft.p(SourceFile:386)
	at bcx.t(SourceFile:1586)
	at bcx.av(SourceFile:968)
	at bcx.a(SourceFile:396)
	at net.minecraft.client.main.Main.main(SourceFile:124)


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

-- Head --
Thread: Client thread
Stacktrace:
	at azy.i(SourceFile:64)
	at azy.<init>(SourceFile:50)
	at azv.<init>(SourceFile:21)
	at azw.a(SourceFile:83)
	at bcx.a(SourceFile:2108)
	at bic.a(SourceFile:212)
	at bft.a(SourceFile:346)
	at bic.a(SourceFile:352)
	at bft.k(SourceFile:409)
	at bft.p(SourceFile:386)

-- Affected screen --
Details:
	Screen name: bga
Stacktrace:
	at bcx.t(SourceFile:1586)
	at bcx.av(SourceFile:968)
	at bcx.a(SourceFile:396)
	at net.minecraft.client.main.Main.main(SourceFile:124)

-- System Details --
Details:
	Minecraft Version: 1.10.2
	Operating System: Windows 7 (amd64) version 6.1
	Java Version: 1.8.0_25, Oracle Corporation
	Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
	Memory: 163840064 bytes (156 MB) / 224641024 bytes (214 MB) up to 4281597952 bytes (4083 MB)
	JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx4G -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
	IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
	Launched Version: 1.10.2
	LWJGL: 2.9.4
	OpenGL: Intel(R) HD Graphics 2000 GL version 3.1.0 - Build 9.17.10.4229, Intel
	GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because OpenGL 3.0 is supported and separate blending is supported.
Shaders are available because OpenGL 2.1 is supported.
VBOs are available because OpenGL 1.5 is supported.

	Using VBOs: Yes
	Is Modded: Probably not. Jar signature remains and client brand is untouched.
	Type: Client (map_client.txt)
	Resource Packs: 
	Current Language: English (US)
	Profiler Position: N/A (disabled)
	CPU: 4x Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz