Form disappear .xdp

There are 2 people,

one is a man who create a template form(the form was created not basic form) for data bindings and own 1 account.

the other who needs to edit the template and do data bindings but when clicking the file (.xdp). all template disappear like a empty template

Obviously, i don't know how to explain the issue. if you need further information, please tell me

Regards,

Thanarat