Django 1.11 | Admin site | add board error

Hello everyone and thanks for the tutorials Vitor!
After deploying my django project on cpanel, the admin site works (www.example.com/admin) and i can register and view my models “boards”… but when i want to add a new one (www.example.com/admin/boards/board/add/) after filling out the fields and clicking (save) i get an error that the url pattern didn’t match

Can any one help!