When I do a post one of the session variables is lost in IE. This webapp works perfectly in Chrome and Firefox. Here is the error: NoMethodError at / undefined method `include?' for nil:NilClass file: welcometo.rb location: xml_file_to_use line: 19 Here is the method that errors: def xml_file_to_use groups = allowed_groups #Which xml file should I write to if (session[:location_group].include? all