Submission file error

Hi, when I submit a file, the submission form is coved by 1 file(s) selected messages.

Here is an Image of the Error

This is my shortcodes:

[flexi-form title="Project Submission" name="my_form" ajax="true" class="pure-form pure-form-stacked"]

[flexi-form-tag type="other" new_type="hidden" name="cat" value="95"]

[flexi-form-tag type="post_title" title="Title" placeholder="Be creative"]

[flexi-form-tag type="file_multiple" title="Click to add Image" class="flexi_drag_file" multiple="true"]

[flexi-form-tag type="article" title="Description" placeholder="What is it? What were some challenges? What are you proud of?" editor="true"]

[flexi-form-tag type="captcha" title="Security"]

[flexi-form-tag type="submit" name="submit" value="Submit Now"]

[/flexi-form]