Greetings
Regarding your firmware error take a look at this post https://communities.intel.com/thread/48176 and this one https://communities.intel.com/thread/45295 , they were having your same error maybe one of them might help you out. Other thing you can try is to manually update your firmware as indicated in the Galileo getting started document section 12 https://communities.intel.com/docs/DOC-22204 . For that you’ll need a serial cable, in case you don’t have one in this post is indicated how to build one http://www.malinov.com/Home/sergey-s-blog/intelgalileo-introduction.
Regards
JPMontero_Intel