Version 5.0.0 beta 10

system/Patterns/ActiveRecord.php

@@ -584,10 +584,19 @@ abstract class ActiveRecord
         $photo = new CoverPhoto;
         if( $file = $this->coverPhotoFile() )
         {
-            $photoOffset = static::$databaseColumnMap[ 'cover_photo_offset' ];
             $photo->file = $file;
-            $photo->offset = $this->$photoOffset ?: 0;
+
+			if( isset( static::$databaseColumnMap[ 'cover_photo_offset' ] ) )
+			{
+				$photoOffset = static::$databaseColumnMap[ 'cover_photo_offset' ];
+				$photo->offset = $this->$photoOffset ?: 0;
+			}
+			else
+			{
+				$photo->offset = 0;
+			}
         }
+
         $photo->editable = $this->canEdit();
         $photo->object = $this;
         return $photo;