error in your roots-cleanup.php?
take a look at your class roots_nav_walker extends Walker_Nav_Menu … does it look like this?
{
function start_el(&$output, $item, $depth, $args)
...
add / replace: $depth = 0, $args = array(), $id = 0
result:
class roots_nav_walker extends Walker_Nav_Menu
{
function start_el(&$output, $item,$depth = 0, $args = array(), $id = 0)
