Question

{section name=i loop=(($data|count)/2) start=0}
<div data-role="controlgroup" data-type="horizontal">
    {section name=ii loop=i start=(i+2)}
    <a href="#" data-role="button" name="buttons" rel="{$page['user'][ii]}">{$user['page'][$page['user'][ii]]}</a>
    {/section}
</div>

Problem is somewhre near {section name=ii loop=i start=(i+2)} because <div data-role="controlgroup" data-type="horizontal"> is empty in source.

Answer 1

Try

{section name=i loop=(($data|@count)/2) start=0}

instead of

{section name=i loop=(($data|count)/2) start=0}