The new Template Designer, previously a Draft Blogger feature, was added to Production Blogger this week. And just as some bloggers are discovering how exciting they are, others are discovering that the Designer templates have downsides.
Fortunately, even though the Template Designer wizard is part of Production (Orange) Blogger, you can revert your blog and recover the Layout template, if you decide that the Designer template isn't to your taste.
Just go to the "Edit Template" wizard, and look at the bottom section "Old Templates". If your blog has a Designer template, you should have a link to "Select Layout Template".
Under "Old Templates", find "Select Layout Template".
Next, pick a new Layout template. Hopefully, you remember how to do this.
Now that the blog has a Layout template again, and hoping that you backed up the Layout template before you setup the Designer template earlier, just restore your backed up Layout template, if you find any remembered details missing.