Drupal 7

Warning: Invalid argument supplied for foreach() in theme_links() (line 1810 of /includes/theme.inc).

When you get this Warning with a sub-theme change this text in template.php (https://www.drupal.org/project/responsive/issues/1820574)

In Theme:

if (isset($vars['main_menu'])) { $vars['main_menu_links'] = $vars['main_menu']; $vars['main_menu'] = theme('links__system_main_menu', array( 'links' => $vars['main_menu_links'], 'attributes' => array( 'class' => array('links', 'main-menu', 'clearfix'), ), 'heading' => array( 'text' => t('Main menu'), 'level' => 'h2', 'class' => array('element-invisible'), ) )); } else { $vars['main_menu'] = FALSE; }

Drupal 7.50 - Just When I Thought I Might Be Getting This Stuff

Funny thing happened with Drupal 7.50, errors started appearing that I had no clue about.  It started telling me about modules not being where they were supposed to be and about a utf-8 not being enabled.  

I was immediately frustrated by this.  All I wished to do was a "simple" upgrade and I'm getting hit with problems.  I abandoned what I was doing and went into hiding.  I have been doing drupal for coming on my 3rd year, and it seems like everytime I feel like I'm starting to get the hang of things something happens and it makes me feel like I'm back to being a beginner.