In Zmodeler Version 2.1.1 it says (missing filter for extension "png") when i try to upload the images. 
the place where the "png" is displayed is replaced with different file types for the ones i want to upload. 
                           e.g - (missing filter for extension "bmp")  
                                   (missing filter for extension "jpg")  
                                    (missing filter for extension "gif") ...and so on.