In reply to David Gard.

Hi David, I'm the author of RFG. There are two likely explanations for this: you didn't put the generated files at the root of your blog, or your didn't submit a high resolution picture (so the bigest pictures were not generated). A third explanation is... that the service is in beta after all :) More on this here: http://realfavicongenerator.net/faq#why_error_after_generation