Generator-jekyllrb is built on top of many open source projects, specifically Jekyll and a number of Grunt plugins.
Before posting, please be sure that your issue is generator-specific. Read the errors and see if you can find fixes in the issue trackers for the projects that throw them, especially Jekyll, Jekyll plugins, or the Ruby executable you're using if you're on Windows.
Jekyll issue tracker: https://github.com/mojombo/jekyll/issues
You can also find help on the freenode #jekyll irc channel. Post, and be patient.
If you're having a hard time figuring out where an error comes from, please post. No issues will be ignored.