Hello,
the first 6 errors I think come from the generated code of megamenu (mega-dropdown-inner)
What I did there as I remember, was the creation of the menu items in the backend, the mega menu configuration in the template manager, and some custom CSS. These steps cannot harm the generated html, do they?
The rest errors indead seam to come from articles and or other modules and customizations.
I wonder if this:
Error: Attribute span12 not allowed on element div at this point.
From line 2255, column 6; to line 2255, column 43
ow">↩ <div class="span12 item-first" span12>↩
comes from the template or is somewhere in some module, or article etc.
Thank you in advance