Selecting DropDown item does not work anymore

Hello,

I had an old project that was working properly with an older version of Radzen.Blazor (2.3.7). I have updated to the latest Radzen.Blazor assembly (2.18.6) and now I get the following error when I select an Item in the a DropDown:

blazor.server.js:19 [2020-12-16T18:21:48.487Z] Error: System.NotSupportedException: Unable to cast the type 'Manu.Application.EcommerceB2B.Contracts.PaisDto' to type 'System.Object'. LINQ to Entities only supports casting EDM primitive or enumeration types.
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.ValidateAndAdjustCastTypes(TypeUsage toType, TypeUsage fromType, Type toClrType, Type fromClrType)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.GetCastTargetType(TypeUsage fromType, Type toClrType, Type fromClrType, Boolean preserveCastForDateTime)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.CreateCastExpression(DbExpression source, Type toClrType, Type fromClrType)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.CastMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.SequenceMethodTranslator.Translate(ExpressionConverter parent, MethodCallExpression call, SequenceMethod sequenceMethod)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.MethodCallTranslator.TypedTranslate(ExpressionConverter parent, MethodCallExpression linq)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.TranslateExpression(Expression linq)
   at System.Data.Entity.Core.Objects.ELinq.ExpressionConverter.Convert()
   at System.Data.Entity.Core.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable`1 forMergeOption)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass41_0.<GetResults>b__1()
   at System.Data.Entity.Core.Objects.ObjectContext.ExecuteInTransaction[T](Func`1 func, IDbExecutionStrategy executionStrategy, Boolean startLocalTransaction, Boolean releaseConnectionOnSuccess)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<>c__DisplayClass41_0.<GetResults>b__0()
   at System.Data.Entity.SqlServer.DefaultSqlExecutionStrategy.Execute[TResult](Func`1 operation)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.GetResults(Nullable`1 forMergeOption)
   at System.Data.Entity.Core.Objects.ObjectQuery`1.<System.Collections.Generic.IEnumerable<T>.GetEnumerator>b__31_0()
   at System.Data.Entity.Internal.LazyEnumerator`1.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at Radzen.DataBoundFormComponent`1.get_View()
   at Radzen.DropDownBase`1.SelectItem(Object item, Boolean raiseChange)
   at Radzen.Blazor.RadzenDropDownDataGrid`1.OnRowSelect(Object item)
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Radzen.Blazor.RadzenGrid`1.OnRowSelect(TItem item, Boolean raiseChange)
   at Microsoft.AspNetCore.Components.ComponentBase.CallStateHasChangedOnAsyncCompletion(Task task)
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

I have tried older versions, and the last one where this was working was 2.15.13

Could you please help me?

I am afraid there is no way for us to help you without a reproduction. If you have a Radzen Professional subscription you can send us your application to info@radzen.com.

In the thread you closed there was a reproduction that shows the problem:

http://85.214.40.25/rz/BlazorRadzenTests.zip

although it is using a dropdowndatagrid