I just wanted to download Shaders and I needed Forge for that, I've used forge before, but suddenly it won't even start the game.

Here's what the crash report says:

---- Minecraft Crash Report ----

// This doesn't make any sense!

 

Time: 1/11/16 1:09 PM

Description: Initializing game

 

java.lang.IllegalStateException: can't pop unfinished ProgressBar Rendering Setup

at net.minecraftforge.fml.common.ProgressManager.pop(ProgressManager.java:35)

at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:492)

at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:326)

at net.minecraft.client.main.Main.main(SourceFile:120)

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 net.minecraftforge.fml.common.ProgressManager.pop(ProgressManager.java:35)

at net.minecraft.client.Minecraft.func_71384_a(Minecraft.java:492)

 

-- Initialization --

Details:

Stacktrace:

at net.minecraft.client.Minecraft.func_99999_d(Minecraft.java:326)

at net.minecraft.client.main.Main.main(SourceFile:120)

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: 1.8

Operating System: Windows 7 (amd64) version 6.1

Java Version: 1.8.0_25, Oracle Corporation

Java VM Version: Java HotSpot 64-Bit Server VM (mixed mode), Oracle Corporation

Memory: 42811928 bytes (40 MB) / 283955200 bytes (270 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: MCP v9.10 FML v8.0.127.1103 2 mods loaded, 2 mods active

mcp{9.05} [Minecraft Coder Pack] (minecraft.jar) Unloaded->Constructed->Pre-initialized

FML{8.0.127.1103} [Forge Mod Loader] (fml-1.8-8.0.127.1103.jar) Unloaded->Constructed->Pre-initialized

Loaded coremods (and transformers):

GL info: ' Vendor: 'ATI Technologies Inc.' Version: '3.2.9232' Renderer: 'ATI Radeon HD 5450'

Launched Version: 1.8-FML8.0.127.1103

LWJGL: 2.9.1

OpenGL: ATI Radeon HD 5450 GL version 3.2.9232, 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: No

Is Modded: Definitely; Client brand changed to 'fml'

Type: Client (map_client.txt)

Resource Packs: [Defscape 64x 2.5.zip]

Current Language: English (US)

Profiler Position: N/A (disabled)

From this video..

Also, never use sites like 9minecraft, 6minecraft or any malicious site like that. This is a thread which was about sites like that, and why you should never use them. And as the 2 year old (!) Youtube video says you have to do, don't do it. You will get these kind of issues when you do.