Why can't I play Minecraft 1.7.10 Single player? I get JsonSyntaxException [duplicate]

Every time I try I get this JsonSyntaxException:

---- Minecraft Crash Report ----
// Ouch. That hurt :(

Time: 8/8/14 8:59 AM
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 ns.b(SourceFile:156)
at ns.<init>(SourceFile:42)
at net.minecraft.server.MinecraftServer.<init>(SourceFile:114)
at bsx.<init>(SourceFile:38)
at bao.a(SourceFile:1610)
at bdx.e(SourceFile:162)
at bdx.a(SourceFile:127)
at bdw.a(SourceFile:172)
at bdw.k(SourceFile:232)
at bdw.p(SourceFile:211)
at bao.p(SourceFile:1328)
at bao.ak(SourceFile:774)
at bao.f(SourceFile:728)
at net.minecraft.client.main.Main.main(SourceFile:148)
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)
... 15 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 ns.b(SourceFile:156)
    at ns.<init>(SourceFile:42)
    at net.minecraft.server.MinecraftServer.<init>(SourceFile:114)
    at bsx.<init>(SourceFile:38)

-- Starting integrated server --
Details:
    Level ID: New World
    Level Name: New World
Stacktrace:
    at bao.a(SourceFile:1610)
    at bdx.e(SourceFile:162)
    at bdx.a(SourceFile:127)
    at bdw.a(SourceFile:172)
    at bdw.k(SourceFile:232)
    at bdw.p(SourceFile:211)

-- Affected screen --
Details:
    Screen name: bee
Stacktrace:
    at bao.p(SourceFile:1328)
    at bao.ak(SourceFile:774)
    at bao.f(SourceFile:728)
    at net.minecraft.client.main.Main.main(SourceFile:148)

-- System Details --
Details:
    Minecraft Version: 1.7.10
    Operating System: Windows 8 (x86) version 6.2
    Java Version: 1.7.0_25, Oracle Corporation
    Java VM Version: Java HotSpot(TM) Client VM (mixed mode), Oracle Corporation
    Memory: 222667112 bytes (212 MB) / 377651200 bytes (360 MB) up to 523501568 bytes (499 MB)
    JVM Flags: 6 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx512M -XX:+UseConcMarkSweepGC -XX:+CMSIncrementalMode -XX:-UseAdaptiveSizePolicy -Xmn128M
    AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    IntCache: cache: 0, tcache: 0, allocated: 13, tallocated: 95
    Launched Version: 1.7.10
    LWJGL: 2.9.1
    OpenGL: AMD Radeon HD 7340 Graphics GL version 4.3.12618 Compatibility Profile Context 13.251.9001.0, ATI Technologies Inc.
    GL Caps: Using GL 1.3 multitexturing.
Using framebuffer objects because OpenGL 3.0 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: []
    Current Language: English (US)
    Profiler Position: N/A (disabled)
    Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    Anisotropic Filtering: Off (1)