http://www.minecraftforum.net/topic/249637-100-optifine-hd-c-fps-boost-hd-textures/If possible start with a clean minecraft.jar and check the mod compatibility section above. schrieb:
Quelle
Windows/Linux Instructions:
1) Locate your minecraft.jar file. On Windows, it's in %APPDATA%/.minecraft/bin
2) Create a backup of minecraft.jar
3) Open minecraft.jar in an archive editor (WinRar/7-Zip/etc)
4) Delete the META-INF folder.
5) Copy the .class files from the downloaded zip file into the jar file, replacing previous files.
6) Run Minecraft and test!