For some reason the server IP stopped working. Sent in a support ticket to our hosting provider. Hopefully it will be fixed soon. (Most likely has to due with increasing the RAM and getting a dedicated IP address.)
If you want to add optifine for the server you want verison OptiFine 1.12.2 HD U F5 and you can find it at https://optifine.net/downloads
It is super easy to install just drag and drop into your mods folder for the FTB pack and then it's installed. :) If you need any help let us know!