When I tried to play my singleplayer world, it crashes Minecraft

When I tried to play singleplayer world, it crashes Minecraft, also the singleplayer world list looks weird from the picture, same thing when I tried to create a new world from Superflat world, etc

---- Minecraft Crash Report ----
// Daisy, daisy...

Time: 4/24/14 4:37 PM
Description: Starting integrated server

com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING at line 1 column 1
at com.google.gson.Gson.fromJson(Gson.java:815)
at com.google.gson.Gson.fromJson(Gson.java:768)
at pd.b(SourceFile:148)
at pd.<init>(SourceFile:42)
at net.minecraft.server.MinecraftServer.<init>(SourceFile:120)
at cim.<init>(SourceFile:34)
at bja.a(SourceFile:1701)
at bmz.e(SourceFile:172)
at bna.a(SourceFile:224)
at blm.a(SourceFile:205)
at bmz.a(SourceFile:197)
at bxg.b(SourceFile:975)
at bja.ai(SourceFile:828)
at bja.f(SourceFile:755)
at net.minecraft.client.main.Main.main(SourceFile:121)
Caused by: java.lang.IllegalStateException: Expected BEGIN_ARRAY but was STRING at line 1 column 1
at com.google.gson.stream.JsonReader.beginArray(JsonReader.java:338)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:79)
at com.google.gson.internal.bind.CollectionTypeAdapterFactory$Adapter.read(CollectionTypeAdapterFactory.java:60)
at com.google.gson.Gson.fromJson(Gson.java:803)
... 14 more

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

– Head –
Stacktrace:
at com.google.gson.Gson.fromJson(Gson.java:815)
at com.google.gson.Gson.fromJson(Gson.java:768)
at pd.b(SourceFile:148)
at pd.<init>(SourceFile:42)
at net.minecraft.server.MinecraftServer.<init>(SourceFile:120)
at cim.<init>(SourceFile:34)

– Starting integrated server –
Details:
Level ID: Test
Level Name: Test
Stacktrace:
at bja.a(SourceFile:1701)
at bmz.e(SourceFile:172)
at bna.a(SourceFile:224)
at blm.a(SourceFile:205)
at bmz.a(SourceFile:197)

– Screen render details –
Details:
Screen name: bnj
Mouse location: Scaled: (301, 62). Absolute: (603, 581)
Screen size: Scaled: (683, 353). Absolute: (1366, 706). Scale factor of 2
Stacktrace:
at bxg.b(SourceFile:975)
at bja.ai(SourceFile:828)
at bja.f(SourceFile:755)
at net.minecraft.client.main.Main.main(SourceFile:121)

– System Details –
Details:
Minecraft Version: 14w17a
Operating System: Windows 7 (amd64) version 6.1
Java Version: 1.7.0_40, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 209509640 bytes (199 MB) / 282066944 bytes (269 MB) up to 954728448 bytes (910 MB)
JVM Flags: 2 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx1G
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
Launched Version: 14w17a
LWJGL: 2.9.1
OpenGL: Intel(R) HD Graphics GL version 2.1.0 - Build 8.15.10.2622, Intel
GL Caps: Using GL 1.3 multitexturing.
Using GL 1.3 texture combiners.
Using framebuffer objects because ARB_framebuffer_object is supported and separate blending is supported.
Anisotropic filtering is supported and maximum anisotropy is 16.
Shaders are available because OpenGL 2.1 is supported.

Is Modded: Probably not. Jar signature remains and client brand is untouched.
Type: Client (map_client.txt)
Resource Packs: [-snip-'s resource pack]
Current Language: English (US)
Profiler Position: N/A (disabled)
Anisotropic Filtering: Off (1)