Yes, I know that it is no longer supported. I noted that I wanted to mod for it because it is the most popular for modpacks. I have no interest in modding for 1.8 or 1.7 until i finish this one, there are mods I want to make my mod work together with that only support 1.6.4.
Do you still know of any way around this error, or is it impossible to mod for 1.6.4 through this method anymore.