"Undefined index: preview_image_style" I have this error message, which I know is related to the multiupload_filefield_widget  module. If I disable this module, the message disappear.


  Notice: Undefined index: preview_image_style in image_field_widget_process() (line 381 of /Applications/MAMP/htdocs/my-site.com/modules/image/image.field.inc).


I found this issue]2 which mention this message but isn't fixed yet. 

How can I solve this?
The error message doesn't show up if you go to the image field settings and, under Image preview style, select a value that actually exist or None.
For some reason, there are several values in that field that don't match with any file in the filesystem; when the code checks this, it finds no such version of the image and emits an error.