Index: src/wp-admin/includes/class-wp-list-table.php
===================================================================
--- src/wp-admin/includes/class-wp-list-table.php	(revision 32712)
+++ src/wp-admin/includes/class-wp-list-table.php	(working copy)
@@ -850,8 +850,16 @@
 	 * @return array
 	 */
 	protected function get_column_info() {
-		if ( isset( $this->_column_headers ) )
+		if ( isset( $this->_column_headers ) ) {
+			while ( sizeof( $this->_column_headers ) < 4 ) {
+				if ( 3 === sizeof( $this->_column_headers ) ) {
+					$this->_column_headers[] = $this->get_primary_column_name();
+				} else {
+					$this->_column_headers[] = array();
+				}
+			}
 			return $this->_column_headers;
+		}
 
 		$columns = get_column_headers( $this->screen );
 		$hidden = get_hidden_columns( $this->screen );