IMPORTANT: Be sure you start the modpack twice the first time after install. Sorry for that issue, it will be fixed in future.
ATTENTION: Be careful with your RAM. Be sure to use more than 6 Gig. Otherwise if you have an SSD the lifetime will be reduced. Your Computer could crash to.
Tested on Linux Fedora 27 and Fedora 28. I suggest the use of Linux based systems.
Make sure you use the right Java version. I suggest the use of the java-1.8.171-openjdk-devel package, with is provided in every Fedora and Gnome based system, but every other version expect for the headless one will just work fine as well.
For 64x bit systems, Java 64x is highly recommended. It will boost your Minecraft to about 20%.