A Layouts template, the template in a New Blogger blog, when published to Blog*Spot (or to a Google Custom Domain) is written in XML, not HTML. A lot of HTML based tweaks won't work in New Blogger. If you force HTML into your template, you may end up with one of the new, cryptic error codes bX-lgwej This says that your post template contains invalid HTML . Are you seeing this error? If so, don't despair. Revert the template back to Classic , so your readers can access the blog. Build a test version of the blog , and work on a New Blogger template, while your readers are accessing the production blog. Take your HTML based template tweaks, that made your Classic blogs unique, and add them as HTML / JavaScript page elements. Test everything, carefully, in all available browsers . When you have a New Blogger template for your blog, looking as you like it, Save the template to a known location. Migrate your production blog to a New Blogger template again. Restore the saved templ...
What Blogger won't tell you