Not selected mapping fields, system not showing validation message

Replication Steps :

1)Open template library page
2)Click on Add new template
3) Fill all mandatory details
4) Upload the pdf document
5) Fields should not be mapped and create template
6) System is not showing validation as form fields, system field and mapping fields are mandatory.

Actual result - System is not showing validation message also not creating document.

Expected result - System should show validation when form fields and system field are not selected and not mapped in mapping fields.