If you are having issues logging into the server now that we are running Ultimate Pack there are a few thing to try.
1. Try adding “-XX:MaxPermSize=128m” to the additional java parameters section under Options>Advanced Options in the launcher. It needs the – in front.
2. If you get an error about TwilightForest download twilight forest from here and reinstall in your mods folder. Remove the existing TwilightForest.zip and place the download in Ultimate\minecraft\mods.
We will add to this post if more fixes become apparent.