Hi Team,
In our Projects, We are using core file upload resourecType(cq/gui/components/authoring/dialog/fileupload), in component dialogs to Allow Authors to Drag Drop Images. Below are the properties we using in dialog for this field. When we Darg Drop Image into these Fields and submit the Dialog, it is always showing error "Please Fill out this field". Any Pointers/Help to resolve this issue is really appreciated. We are using AEM 6.3.2.2
<heroImage
jcr:primaryType="nt:unstructured"
sling:resourceType="cq/gui/components/authoring/dialog/fileupload"
allowUpload="{Boolean}false"
autoStart="{Boolean}false"
class="cq-droptarget"
fieldDescription="Choose Hero Image"
fieldLabel="Hero Image"
fileReferenceParameter="./heroImage"
mimeTypes="[image]"
multiple="{Boolean}false"
name="./heroImages"
required="{Boolean}true"
uploadUrl="${suffix.path}"
useHTML5="{Boolean}true"/>

Thanks
K Chaitanya