There is an error when filename is a part of article id. For example filename is "4.jpg" and article id is "324". Path to file is "/images/type_name/324/4.jpg", but path to thumb in this case is "/images/type_name/32_thumb1/4/_thumb1/4.jpg". So, such thumb is anavailiable.
My correction limits filename between slash and dot to define filename more clear.
There is an error when filename is a part of article id. For example filename is "4.jpg" and article id is "324". Path to file is "/images/type_name/324/4.jpg", but path to thumb in this case is "/images/type_name/32_thumb1/4/_thumb1/4.jpg". So, such thumb is anavailiable. My correction limits filename between slash and dot to define filename more clear.