[drupal-support] Upgraded to 4.5.4

I just upgraded to 4.5.4 from 4.4.2, and while the upgrade went pretty smoothly, I'm now getting the error message: warning: Invalid argument supplied for foreach() in [[path to Drupal]]/www/themes/arrow/arrow.theme on line 117 when I first access the site. The home page displays correctly, and if I refresh the page or click to a second page, the error message goes away. Any ideas what's wrong? Thanks, Dan