I added a new ADO.Net Entity Data Model into my project and used the Update Wizard to add tables into the model. Five of the selected tables were added to the design surfac
My solution to this is to delete the entire model and readd it including the new tables that I want.
I accidentally deleted a table in the designer once and could not readd it. Hence removing entire model and readding it.
I had some issues with this as well (Ado.Net Entity Data Model Not Updating Correctly)