Multiplicity constraint violated - entity-framework

Question

I have two entites:
ClaimDetail (int ID, IList ClaimDetailStatus, other...)
ClaimDetailStatus (int ID, ClaimDetailClaimDetail, other...)
Configuration:
modelBuilder.Entity<ClaimDetailStatus>()
.HasRequired<ClaimDetail>(x => x.ClaimDetail)
.WithMany(x => x.ClaimDetailStatus)
.HasForeignKey(x => x.ClaimDetailID).WillCascadeOnDelete(true);
modelBuilder.Entity<ClaimDetail>()
.HasMany<ClaimDetailStatus>(x => x.ClaimDetailStatus)
.WithRequired(x => x.ClaimDetail)
.HasForeignKey(x => x.ClaimDetailID).WillCascadeOnDelete(true);
When i'm writing the code, running & debug it everything is fine but when i want to save everything it throws an exception:
System.InvalidOperationException was unhandled by user code
HResult=-2146233079
Message=Multiplicity constraint violated. The role 'ClaimDetailStatus_ClaimDetail_Target' of the relationship 'EPer.DataAccess.ClaimDetailStatus_ClaimDetail' has multiplicity 1 or 0..1.
Source=System.Data.Entity
StackTrace:
at System.Data.Objects.DataClasses.EntityReference`1.AddToLocalCache(IEntityWrapper wrappedEntity, Boolean applyConstraints)
at System.Data.Objects.EntityEntry.TakeSnapshotOfSingleRelationship(RelatedEnd relatedEnd, NavigationProperty n, Object o)
at System.Data.Objects.EntityEntry.TakeSnapshotOfRelationships()
at System.Data.Objects.DataClasses.RelatedEnd.AddEntityToObjectStateManager(IEntityWrapper wrappedEntity, Boolean doAttach)
at System.Data.Objects.DataClasses.RelatedEnd.AddGraphToObjectStateManager(IEntityWrapper wrappedEntity, Boolean relationshipAlreadyExists, Boolean addRelationshipAsUnchanged, Boolean doAttach)
at System.Data.Objects.DataClasses.RelatedEnd.IncludeEntity(IEntityWrapper wrappedEntity, Boolean addRelationshipAsUnchanged, Boolean doAttach)
at System.Data.Objects.DataClasses.EntityCollection`1.Include(Boolean addRelationshipAsUnchanged, Boolean doAttach)
at System.Data.Objects.DataClasses.RelationshipManager.AddRelatedEntitiesToObjectStateManager(Boolean doAttach)
at System.Data.Objects.ObjectContext.AddObject(String entitySetName, Object entity)
at System.Data.Entity.Internal.Linq.InternalSet`1.ActOnSet(Action action, EntityState newState, Object entity, String methodName)
at System.Data.Entity.Internal.Linq.InternalSet`1.Add(Object entity)
at System.Data.Entity.DbSet`1.Add(TEntity entity)
at EPer.DataAccess.ObjectSetAdapter`1.AddObject(T entity) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer.Dal\ObjectSetAdapter.cs:line 41
at EPer.BusinessLogic.DomainServices.ClaimComponent.CreateClaim(Claim claimModel, UserClaim uc) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer.BusinessLogic\DomainServices\ClaimComponent.cs:line 28
at EPer.BusinessLogic.ApplicationServices.ClaimService.CreateClaim(Claim claimModel, IEnumerable`1 autoApprovers, UserClaim uc) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer.BusinessLogic\ApplicationServices\ClaimService.cs:line 180
at EPer.BusinessLogic.ApplicationServices.ClaimService.CreateClaim(Claim claimModel, IEnumerable`1 autoApprovers) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer.BusinessLogic\ApplicationServices\ClaimService.cs:line 113
at EPer.BusinessLogic.ApplicationServices.ClaimService.CreateClaim(Claim claimModel) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer.BusinessLogic\ApplicationServices\ClaimService.cs:line 99
at EPer.Areas.Claims.Controllers.ClaimController.Create(SingleClaim m) in c:\KBData\_repo\Intranet\Apps\EOffice\EPer\EPer\Areas\Claims\Controllers\ClaimController.cs:line 107
at lambda_method(Closure , ControllerBase , Object[] )
at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33()
at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49()
InnerException:
Generated association:
<Association Name="ClaimDetailStatus_ClaimDetail">
<End Role="ClaimDetailStatus_ClaimDetail_Source" Type="Self.ClaimDetailStatus" Multiplicity="*" />
<End Role="ClaimDetailStatus_ClaimDetail_Target" Type="Self.ClaimDetail" Multiplicity="1">
<OnDelete Action="Cascade" />
</End>
<ReferentialConstraint>
<Principal Role="ClaimDetailStatus_ClaimDetail_Target">
<PropertyRef Name="ID" />
</Principal>
<Dependent Role="ClaimDetailStatus_ClaimDetail_Source">
<PropertyRef Name="ClaimDetailID" />
</Dependent>
</ReferentialConstraint>
I have checked the generated visualized Entity Data Model and everything looked okay.
What is happening here?
EDIT correction
I have a 3rd entity: Claim; if a Claim contains only one ClaimDetail everything works fine but if it contains 2 ClaimDetail the above exception is thrown.

Answer 1

The problem was that i added to each of the ClaimDetail's ClaimDetailStatus collection the same instance of the first ClaimDetailStatus. If i'm adding different instances (in a cycle detail.ClaimDetailStatus.Add(new ...)) everything works fine.

Answer 2

ClaimDetail (int ID, IList ClaimDetailStatus, other...)
ClaimDetailStatus (int ID, ClaimDetailClaimDetail, other...)
This happened when I got entity from db, then tried to save the edited one.
Try
Detached ClaimDetail.ClaimDetailStatus.ClaimDetailClaimDetail,
ClaimDetail.ClaimDetailStatus,
ClaimDetail
Then save, it works.