I installed Forge 6.6.2.534 and IC2 then decompiled the jar with MCP and I ended up getting this error:
Code
21:28:38 - ERROR: duplicate entry: net/minecraft/src/GuiAchievements.class21:28:38 - '"java" -cp "runtime/bin/retroguard.jar:lib:lib/*:jars/bin/minecraft.jar:jars/bin/jinput.jar:jars/bin...' failed : 121:28:38 - 21:28:38 - == ERRORS FOUND ==21:28:38 - 21:28:38 - Unrecoverable error during obfuscation, see log file for details.21:28:38 - ERROR: duplicate entry: net/minecraft/src/GuiAchievements.class21:28:38 - ==================21:28:38 - 21:28:38 - Decompile failedCan someone help me install IC2 along with the API so I can make an addon?