WordPress: wp.media.frame doesn’t display attachment

I am using the wp.media frame uploader in my plugin to upload files. It works perfectly as it should except one problem.
When I upload file (using upload button, or drag and drop) it uploads the file and displays its information in sidebar menu, but doesn’t display thumbnail of attachment. Its a kind of annoying problem because first its a default behaviour on wp.media and second same implementation is working fine on different plugin. Has anyone come across this problem..

Code I used is:

    var alex_doc_uploader = $thisButton.data('file_frame');
    if (alex_doc_uploader) {
        alex_doc_uploader.open();
        return;
    }

    // Create the media frame.
    alex_doc_uploader = wp.media.frames.file_frame = wp.media({
        title: "Select Documents",
        button: {
            text: "Select Documents"
        },
        library : {
          type:   accepted_mime_types
        },
        multiple: true  // Set to true to allow multiple files to be selected
    });

    $thisButton.data('file_frame', alex_doc_uploader);

And when i upload a file,

The result I get is

But what should happen is