There are seveal places you can go to get support for FTB related issues, we will always try our best to solve any issues with the launcher or modpacks however in most cases issues with the modpacks are with specific mods within the modpack if this is the case then you should contact the specific mod authors with a bug report.
The first port of call if you need support should always be a search engine, make a google search for the problem you are having or put the error into google and see if they are any results that solve your problem.
If you are unsuccessful in finding an existing answer to your issue you can visit our support forumss, make an account and submit a new topic for the community to help you.
Do a google search for the error you are getting to see if anyone has already found the fix for your problem
If you can't find the fix for your problem then make a post in the support site or ask in IRC but be sure to follow IRC etiquette
Be patient, give people a decent amount of time to respond, that means no bumping or reposting repeatedly in IRC, it'll only get you kicked or a warning, if you don't get an answer after a few hours then either ask again in IRC or create a support topic