title: Entity Framework 4.0: Error 113: Multiplicity is not valid in Role
body: <p>I have put a new table in my database and there are 4 tables that have a foreign key relationship with it.
  I thought I configured all 4 in the same way, but I get this error;</p>
  
  <blockquote>
    <p>Error 15  Error 113: Multiplicity is not valid in Role 'ReportCellImage' in relationship 'FK_OtherLeaves_ReportCellImages'. Because all the properties in the Dependent Role are nullable, multiplicity of the Principal Role must be '0..1'. </p>
  </blockquote>
  
  <p>So to simplify my tables;</p>
  
  <p>ReportCellImage table contains the
  ReportCellImageId field which in the primary key and an integer</p>
  
  <p>OtherLeave table contains the 
  ReportCellImageId field as a nullable foreign key with a default of 4</p>
  
  <p>The other tables are similar and all have a foreign key configured to join with the ReportCellImage table</p>
  
  <p>This is a recent change, so when I update my edmx file from the database, why do I get this error and how do I fix it?</p>