Well, as of October 2nd the Minecraft Forge repo no longer distributes the library files needed. With the new launcher, this is not an issue (we automagickally mirror them on our repo), but since we never added them in the FTB distribution we’re a little in trouble.
Download this zip archive, extract it to (your FTB base folder)/FrogTEK/minecraft/lib. That will fix you up until we start with the new launcher.
PLEASE NOTE: You do not have to download this unless you are making a new install of the mod pack. Also, super gentle reminder – You need to sign up for whitelist in the forum to get whitelisted (note: not our ExtraLife post or on FSMC, our forum).