Not working when used with entity reference

When using a multiple value entity reference i get the following errors:

Notice: Undefined index: #entity_type in multiple_value_widget_field_multiple_value_form() (line 56 of multiple_value_widget.module).
Notice: Undefined index: #field_name in multiple_value_widget_field_multiple_value_form() (line 56 of multiple_value_widget.module).
Notice: Undefined index: #bundle in multiple_value_widget_field_multiple_value_form() (line 56 of multiple_value_widget.module).

An entity reference stores its field information on target_id.