Check out the official Tekxit reddit! https://www.reddit.com/r/Tekxit/
The first Tekxit is now able to be downloaded again if you wish to do so :)
If modpack wont start, open launcher>click Tekxit>modpack options>open>delete all except cache> return to launcher>reinstall>try playing; If not fixed please click modpack options>open>open logs folder>upload fml-client-latest.log and send me a link.