Hi,

I imagine you'd get such error if the control fails to instantiate your custom nodes for some reason. Try comparing your code with CustomNodes sample project to see how custom nodes are registered and handled in current version. Otherwise could you attach a test project reproducing that, or show some snippets from your code that register custom types and populate the diagram?

Regards,
Slavcho
Mindfusion

the way data is gathered from diagram is flowChart.toJson(). json string is about 10% bigger in new version

We are using .net 4.8.

code snippet:
public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
        {
            var node = obj as T;
            if (node != null)
            {
                IDictionary<string, object> json = base.Serialize(obj, serializer);
                return json;
            }
            return null;
        }

stack trace:
   at System.Web.Script.Serialization.ObjectConverter.ConvertDictionaryToObject(IDicti
onary`2 dictionary, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)
   at System.Web.Script.Serialization.ObjectConverter.ConvertObjectToTypeInternal(Obje
ct o, Type type, JavaScriptSerializer serializer, Boolean throwOnError, Object& convertedObject)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal
(Int32 depth)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeList(Int
32 depth)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal
(Int32 depth)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeDictiona
ry(Int32 depth)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.DeserializeInternal
(Int32 depth)
   at System.Web.Script.Serialization.JavaScriptObjectDeserializer.BasicDeserialize(St
ring input, Int32 depthLimit, JavaScriptSerializer serializer)
   at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize(JavaScriptSeria
lizer serializer, String input, Type type, Int32 depthLimit)
   at System.Web.Script.Serialization.JavaScriptSerializer.Deserialize[T](String input)
   at MindFusion.Diagramming.Mvc.DiagramView.LoadJson(String json, Boolean clearDiagram)
   at OACloud.Web.Controllers.WorkflowProcessDefinitionVersionController.UpdateVersion
Diagram() in C:\mindfusion\OAModules\OACloud.Web.Controllers\Admin\Configuration\Workflow\Wor
kflowProcessDefinitionVersionController.cs:line 391
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c.<BeginInvokeSynchronousAct
ionMethod>b__9_0(IAsyncResult asyncResult, ActionInvocation innerInvokeState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncResult`2.CallEndDelegate(IAs
yncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncRe
sult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c
__DisplayClass11_0.<InvokeActionMethodFilterAsynchronouslyRecursive>b__0()
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.AsyncInvocationWithFilters.<>c
__DisplayClass11_2.<InvokeActionMethodFilterAsynchronouslyRecursive>b__2()

What's the type of your WfState property, and have you created a JS serializer for it if a complex type? The exception comes from Deserialize method, so please post code for it too.

        [Serializable]
        [TableMapping(TableName = "wf_state")]
        public class WfState : PersistentObjectWithTypedId<Guid>
        {
            public WfState()
            {
                PreConditions = new List<WfCondition>();
                PostConditions = new List<WfCondition>();
            }

            [ColumnMapping(ColumnName = "state_id")]
            public override Guid Id { get; set; }

            [ColumnMapping(ColumnName = "state_name")]
            public string StateName { get; set; }

            [ColumnMapping(ColumnName = "parent_state_id")]
            public Guid? ParentStateId { get; set; }

            [ColumnMapping(ColumnName = "activity_id")]
            public Guid ActivityId { get; set; }

            [ColumnMapping(ColumnName = "is_start")]
            public bool IsStart { get; set; }

            [ColumnMapping(ColumnName = "is_end")]
            public bool IsEnd { get; set; }

            [ColumnMapping(ColumnName = "process_def_version_id")]
            public Guid ProcessDefVersionId { get; set; }

            [ColumnMapping(ColumnName = "field_set_id")]
            public Guid? FieldSetId { get; set; }

            [ColumnMapping(ColumnName = "location_x")]
            public int LocationX { get; set; }

            [ColumnMapping(ColumnName = "location_y")]
            public int LocationY { get; set; }

            [ColumnMapping(TableName = "wf_state_param", IsCollection = true, IsReadOnly = false, FKColumnName = "state_id", FKPropertyValueField = "Id")]
            public IList<WfStateParam> WfStateParams { get; set; }

            public IList<WfCondition> PreConditions { get; set; }

            public IList<WfCondition> PostConditions { get; set; }

        }

yes it is defined in a separate assembly

I changed custom node registration from MindFusion.AbstractionLayer.registerClass(MindFusion.Diagramming.BaseNode, "BaseNode", MindFusion.Diagramming.ShapeNode);

to MindFusion.AbstractionLayer.registerClass(MindFusion.Diagramming.BaseNode, "MindFusion.Diagramming.BaseNode", MindFusion.Diagramming.ShapeNode);