Unable to cast object of type ' . ' to type ' . '.

Interesting issue.. I converted an EDMX -- Thanks again Jeremy for the nightly fix! -- and fixed a few mis-mapped fields using the Key Property Reference. The model now builds, but any basic query throws the exception; Unable to cast object of type ' . ' to type ' . '. I dropped the full stacktrace below.

Not really clear on whether I'm doing something wrong or my model has a problem.. Has anyone seen this before?

System.InvalidCastException was unhandled
  HResult=-2147467262
  Message=Unable to cast object of type ' . ' to type ' . '.
  Source=Mindscape.LightSpeed
  StackTrace:
       at Mindscape.LightSpeed.Model.TypeModel.FindValueModel(String name)
       at Mindscape.LightSpeed.Model.TypeModel.InitializeAssociations(IEnumerable`1 fields, ICollection`1 associationModels)
       at Mindscape.LightSpeed.Model.TypeModel.InitializeFields(ICollection`1 associationModels)
       at Mindscape.LightSpeed.Model.TypeModel.LoadFields(IEnumerable`1 typeModels)
       at Mindscape.LightSpeed.Model.TypeModel.GetTypeModel(Type type)
       at  . . (String , IdentifierExpression , Query )
       at Mindscape.LightSpeed.UnitOfWork.Calculate(String calculation, IdentifierExpression attribute, Query query)
       at Mindscape.LightSpeed.UnitOfWorkBase.Calculate(String calculation, String attribute, Query query)
       at Mindscape.LightSpeed.UnitOfWork.Count(Query query)
       at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.<>c__DisplayClass9.<ExecuteCountCore>b__8()
       at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ChooseCountImplementation[T](Func`1 countByFilteringList, Func`2 countAttribute, Func`1 countEntities)
       at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ExecuteCountCore(IUnitOfWork unitOfWork)
       at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ExecuteCount(IUnitOfWork unitOfWork)
       at Mindscape.LightSpeed.Linq.Plan.SingleQueryPlan.ExecuteImmediate(IUnitOfWork unitOfWork, Type returnType)
       at Mindscape.LightSpeed.Linq.LinqQueryProvider.Execute(Expression expression)
       at Mindscape.LightSpeed.Linq.LinqQueryProvider.System.Linq.IQueryProvider.Execute[S](Expression expression)
       at System.Linq.Queryable.Count[TSource](IQueryable`1 source)
       at LightspeedConversion.Program.UseUnitOfWork() 
       at LightspeedConversion.Program.Main(String[] args)
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: 

I believe you may have this sorted but if not check that you are not setting a value for Key Property Reference when the association is not targeting a composite key based entity. This error is consistent with a value being set where the entity is using a normal identity type.

Jeremy

Hi, I am having the exact same issue.

 Dim afbResult = From HI In DB.HiveAfbInfections
                            Where HI.HiveId = HiveId AndAlso HI.PotentialInfection = True
                            Order By HI.DateCleared.HasValue Ascending, HI.DateCleared
                            Select HI.DateCleared
                            Take 1
            Return afbResult.FirstOrDefault() Is Nothing

This, or any toList(), Any(), etc. applied to the LINQ query is throwing an exception with the message Unable to cast object of type ' . ' to type ' . '.

I don't understand your reply regarding the value for the key property reference. Could you explain further to a complete Lightspeed beginner please?

I want to query a table, get the first result after ordering by, and check whether that result is null in database (as the field is a Nullable datetime). But I am getting this kind of Invalid Cast exception with no details about what type is trying to cast so I am very stuck here..

PS: This is the entity:

<entity name="HiveAfbInfection" identityType="Int64" cacheExpiry="0" schema="Mobile">
  <entityProperties>
    <entityProperty name="DateInfected" dataType="DateTime" privateSetter="false" />
    <entityProperty name="DateCleared" dataType="DateTime" isNullable="true" privateSetter="false" />
    <entityProperty name="PotentialInfection" dataType="Boolean" privateSetter="false" />
    <entityProperty name="CreatedDate" dataType="DateTime" privateSetter="false" />
    <entityProperty name="LastUpdatedDate" dataType="DateTime" isNullable="true" privateSetter="false" />
  </entityProperties>
</entity>

I got a workaround as I suspect that the problem is with the Order By HI.DateCleared.HasValue Ascending part but the I'm not sure if the cast exception not specifying what is the casting being attempted is related to this.

Anyway, I changed my approach and now I have the following working and not crashing when converting to List or applying a count.

 Using DB As LandDataModelUnitOfWork = Context.CreateUnitOfWork
            Dim afbResult = (From HI In DB.HiveAfbInfections
                            Where HI.HiveId = HiveId AndAlso HI.PotentialInfection = False AndAlso HI.DateCleared Is Nothing
                            Order By HI.DateCleared Ascending
                            Select HI).Count()
            Return afbResult > 0
        End Using