DropZone is only show square

[DianDN]

I use dropzone from perminder-klair/yii2-dropzone but why drop zone is only show the square?
Like this

[dragos-popescu]

From your screenshot, I believe it's the same issue I had. I found the fix in the documentation http://www.dropzonejs.com/

// Disabling autoDiscover, otherwise Dropzone will try to attach twice.
Dropzone.autoDiscover = false;

So all you need to do is add this line of code in a JavaScript file:
Dropzone.autoDiscover = false;