title: Foreign Key fails to create
body: <p>I want a foreign key between 2 tables , so i try it like i always do. Now the issue i'm having is he fails to create , and by the looks of it it fails to create because there is already a key but there isnt.</p>
  
  <pre><code>- Unable to create relationship 
   'FK_tbl_Paramed_RegistratieBehandelingen_Users'.  
    The ALTER TABLE statement conflicted with the 
    FOREIGN KEY constraint "FK_tbl_Paramed_RegistratieBehandelingen_Users". 
    The conflict occurred in database "Nestor_Server", 
    table "dbo.Users", column 'UserID'.
  </code></pre>
  
  <p>Ive checked if they have the same type , they do(bigint) so don't get why he won't create it</p>