Replication steps :

1)Open the URL of Create document template
2)Check the checkbox of "Does this form required an expiration date?"
3)Enter "Valid From" and "Valid To" date manually through Keyboard (Eg-05051990)
4)System is showing Validation message as "Please Enter Valid From Date" on click of create template

Expected Result :
When the "Valid From" and "Valid To" date is entered manually through keyboard, system should automatically convert into MM/DD/YYYY format as specified in requirement.
Same issue exists for Edit template, Add new template from Template library.