my game keeps crashing here is the crash log while using the Forge 1.7.10 of course 

---- Minecraft Crash Report ----
// I let you down. Sorry

Time: 06.10.17 12:31
Description: Initializing game

java.lang.NoClassDefFoundError: caa
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Class.java:2575)
    at java.lang.Class.getField0(Class.java:2967)
    at java.lang.Class.getField(Class.java:1693)
    at cpw.mods.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:277)
    at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:192)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:878)
    at net.minecraft.client.main.Main.main(SourceFile:148)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: caa
    at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:191)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 15 more
Caused by: java.lang.NullPointerException
    at net.minecraft.launchwrapper.LaunchClassLoader.findClass(LaunchClassLoader.java:182)
    ... 17 more

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

-- Head --
Stacktrace:
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Class.java:2575)
    at java.lang.Class.getField0(Class.java:2967)
    at java.lang.Class.getField(Class.java:1693)
    at cpw.mods.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:277)
    at cpw.mods.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:192)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:480)

-- Initialization --
Details:
Stacktrace:
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:878)
    at net.minecraft.client.main.Main.main(SourceFile:148)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
    Minecraft Version: 1.7.10
    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: 116661792 bytes (111 MB) / 198598656 bytes (189 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
    AABB Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: 
    Launched Version: 1.7.10-Forge10.13.4.1614-1.7.10
    LWJGL: 2.9.1
    OpenGL: Radeon X1600/X1650 Series  GL version 2.1.8545 Release, ATI Technologies Inc.
    GL Caps: Using GL 1.3 multitexturing.
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: Definitely; Client brand changed to 'fml,forge'
    Type: Client (map_client.txt)
    Resource Packs: []
    Current Language: ~~ERROR~~ NullPointerException: null
    Profiler Position: N/A (disabled)
    Vec3 Pool Size: 0 (0 bytes; 0 MB) allocated, 0 (0 bytes; 0 MB) used
    Anisotropic Filtering: Off (1)

 

1.7.10 is no longer supported here.

You will need to update for support.