I have tried several times uninstalling Minecraft and all forges and I'm still getting this error:

 

The game crashed whilst initializing game
Error: java.lang.NoClassDefFoundError: cer

 

 

---- Minecraft Crash Report ----

WARNING: coremods are present:
Contact their authors BEFORE contacting forge

// Don't do that.

Time: 17/11/18 10:15 PM
Description: Initializing game

java.lang.NoClassDefFoundError: cer
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
    at java.lang.Class.getField0(Class.java:2975)
    at java.lang.Class.getField(Class.java:1701)
    at net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:291)
    at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:203)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:439)
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:351)
    at net.minecraft.client.main.Main.main(SourceFile:124)
    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:497)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)
Caused by: java.lang.ClassNotFoundException: cer
    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 --
Thread: Client thread
Stacktrace:
    at java.lang.Class.getDeclaredFields0(Native Method)
    at java.lang.Class.privateGetDeclaredFields(Class.java:2583)
    at java.lang.Class.getField0(Class.java:2975)
    at java.lang.Class.getField(Class.java:1701)
    at net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:291)
    at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:203)
    at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:439)

-- Initialization --
Details:
Stacktrace:
    at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:351)
    at net.minecraft.client.main.Main.main(SourceFile:124)
    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:497)
    at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
    at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
    Minecraft Version: 1.10.2
    Operating System: Windows 10 (amd64) version 10.0
    Java Version: 1.8.0_51, Oracle Corporation
    Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
    Memory: 879410696 bytes (838 MB) / 1140850688 bytes (1088 MB) up to 2147483648 bytes (2048 MB)
    JVM Flags: 8 total; -XX:HeapDumpPath=MojangTricksIntelDriversForPerformance_javaw.exe_minecraft.exe.heapdump -Xmx2G -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC -XX:G1NewSizePercent=20 -XX:G1ReservePercent=20 -XX:MaxGCPauseMillis=50 -XX:G1HeapRegionSize=32M
    IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
    FML: 
    Loaded coremods (and transformers): 
    Launched Version: 1.10.2-forge1.10.2-12.18.3.2185
    LWJGL: 2.9.4
    OpenGL: AMD Radeon R5 Graphics GL version 4.5.13541 Compatibility Profile Context 25.20.14003.1010, ATI Technologies Inc.
    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: Definitely; Client brand changed to 'fml,forge'
    Type: Client (map_client.txt)
    Resource Packs: 
    Current Language: ~~ERROR~~ NullPointerException: null
    Profiler Position: N/A (disabled)
    CPU: 4x AMD A10-9600P RADEON R5, 10 COMPUTE CORES 4C+6G

2 hours ago, Sb3rik said:

Minecraft Version: 1.10.2

You should use a more recent version of minecraft.

What Optifine version do you have installed?

Optifine only works on specific versions of Forge, and

2 hours ago, Sb3rik said:

1.10.2-forge1.10.2-12.18.3.2185

may not be a version it supports