luacs1998

Block ID error.

Then looks like a OpenGL error. Update LWJGL, there's a guide on the minecraft wiki.

Reinstall.

Either you or the mod. Reminder, the highest block id you can set is 4095.

Extract http://files.minecraftforge.net/fmllibs/fml_libs.zip to your .minecraft/lib folder.

What is running in the background? EXA: Steam, Hamachi, teamspeak... I'm actually quite surprised that you play on a netbook, you know.

For once, I direct you to the ModLoader thread (not to download it, but rather, for Risu's excellent instructions) There's a install tutorial for mac. Or just use MultiMC or Magic Launcher.

As far as I know, for now, you'll have to remove the mod from your (core)mods folder. If it's a jar mod, sorry.

It's supposed to, dumbass.

Could be a CodecIBXM crash, it's the number 1 thing we troubleshoot here. MERGE, not replace.

yeah, I was going at it in the night, and found that the mod that I want to use is the one that give me problems... rei's mini map. runned the game without that... and everything seems working... That is all?

ForgeModLoader-client-0.log exists for a reason. Otherwise, if you can reproduce this issue without forge, I'd say that you need a better computer.

It's not MCPatcher, it's a bad optifine install.

Well, he's not even a modder if he doesn't even know how to use mcp.

"A free alternative to the main Minecraft web services" Sounds familiar? In short, allows users to log on without going through Mojang.

The patches it makes don't really like FML. EDIT: Not our problem, theirs. Get them to fix their launcher.

Jenkins is your answer.

You have an invalid jar, force update and reinstall.

No Player API/Dimension API/stuff like that? Well, why is the Minecraft version null?

Make sure all dependencies have been properly fixed.

Does it? Show us what exactly happens with forge.

Logs don't tell me anything.

Logs?

Always use MCNostalgia/MultiMC for downgrading.

Update forge.