So I've downloaded the latest version of Forge (1.9.4, 1906), and I also have the latest version of Optifine (1.9.4) in my mods folder, I have downloaded Forge 1.8.9 before and it worked fine, whenever I remove OptiFine from the mods folder Forge works, but now when I try to launch any version of Forge it brings up this message:
---- Minecraft Crash Report ----

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

// But it works on my machine.

Time: 5/17/16 4:22 PM
Description: Initializing game

java.lang.VerifyError: Inconsistent stackmap frames at branch target 21
Exception Details:
Location:
Config.getWorldServer()Lnet/minecraft/world/WorldManager; @21: getstatic
Reason:
Type 'net/minecraft/client/network/NetHandlerPlayClient' (current frame, locals[0]) is not assignable to 'net/minecraft/world/World' (stack map, locals[0])
Current Frame:
bci: @16
flags: { }
locals: { 'net/minecraft/client/network/NetHandlerPlayClient' }
stack: { 'net/minecraft/client/network/NetHandlerPlayClient' }
Stackmap Frame:
bci: @21
flags: { }
locals: { 'net/minecraft/world/World' }
stack: { }
Bytecode:
0x0000000: b200 75c7 0005 01b0 b200 75b4 0523 4b2a
0x0000010: c700 0501 b0b2 0075 b605 279a 0005 01b0
0x0000020: b200 75b6 052a 4c2b c700 0501 b02a b405
0x0000030: 304d 2cc7 0005 01b0 2cb6 0536 4e2b 2db6
0x0000040: 053b b605 3e3a 0419 04b0 3a04 01b0
Exception Handler Table:
bci [61, 73] => handler: 74
Stackmap Table:
same_frame(@8)
append_frame(@21,Object[#1317])
same_frame(@32)
append_frame(@45,Object[#1324])
append_frame(@56,Object[#1330])
full_frame(@74,{Object[#1317],Object[#1324],Object[#1330],Object[#1336]},{Object[#1312]})

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 net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:283)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:195)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:434)
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:346)
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:483)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)


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 net.minecraftforge.fml.client.FMLClientHandler.detectOptifine(FMLClientHandler.java:283)
at net.minecraftforge.fml.client.FMLClientHandler.beginMinecraftLoading(FMLClientHandler.java:195)
at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:434)

-- Initialization --
Details:
Stacktrace:
at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:346)
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:483)
at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)
at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

-- System Details --
Details:
Minecraft Version: 1.9
Operating System: Windows 10 (amd64) version 10.0
Java Version: 1.8.0_25, Oracle Corporation
Java VM Version: Java HotSpot(TM) 64-Bit Server VM (mixed mode), Oracle Corporation
Memory: 117672896 bytes (112 MB) / 296808448 bytes (283 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
IntCache: cache: 0, tcache: 0, allocated: 0, tallocated: 0
FML:
Loaded coremods (and transformers):
Launched Version: 1.9-forge1.9-12.16.1.1906
LWJGL: 2.9.4
OpenGL: GeForce 9500 GT/PCIe/SSE2 GL version 3.3.0, NVIDIA Corporation
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 Intel(R) Core(TM) i3-3220 CPU @ 3.30GHz
I'm trying to launch Forge with minecraft so I can be able to enter the server Guildcraft, I have tried reinstalling forge many times and it did not work, I also have Java update 91, is there any fix?