Mystical World has some broken textures with underground biomes, theres a resource pack that fixes it. If you have trouble running the modpack please make sure you have at least 4 Gigs of RAM allocated and a CPU that's at least @ 3.20 GHz. If you continue to have problems set dynamic lights to fast.
Install littlerock's Enhanced Survival
Step 1
Installing a modpack using the Technic Launcher is easy. If you don't already have the launcher downloaded, visit our download page to get the latest version.
Step 2
Type in the modpack name (littlerock's Enhanced Survival) or paste the following url into the search box.
Step 3
Finally, click Install at the bottom right of the launcher after you select littlerock's Enhanced Survival from the list on the left. The launcher will handle everything else!