Breeze underlying array is null error at save

Question

I got the "500 (Internal Server Error) underlying error is null" error message when I want to save the entity I created.

Scenario:

• the user opens a modal window where he can create/edit blog entry
• he can select tags
• he also can create new tags
• if there is a tag which doesn't exist yet then the system creates it automatically

The error occurs when the system want to save the new tag. What I really don't get is which array is null?! If I write out the newly created entity then I see a healthy entity created by breeze and there is no null value, except one (blog description field, but it is not a required field)

What I did to find to locate the defect:

• double-check the code - done
• checking caching - done - it is disabled
• googling - done - it seems it is a very rare issue
• place the code into the controller whether it is a scoping issue - done - the result is the same
• checking the REST controller, it was changed 71 days ago last time, however, in other cases it works well
• sleeping... sometimes it helps - done, it was awesome but it didn't help
• restart the machine - done - nothing
• I think I ran out of ideas...

Here is the code. Nothing new in it. Code like this works without any problem in other places in the app.

This function is called by onTagAdding method of ngTags-input stuff and it is placed in a service.

function onTagAdding(tag)
        {
            console.log("ontagadding");
            var select = 'id, name';
            var p = new Predicate('name', FilterQueryOp.Equals, tag.name);

            datacontext.tag.getAll(select, p).then(function (result)
            {
                if (result.length < 1)
                {
                    //add new tag
                    var newTag = datacontext.tag.create();
                    newTag.name = tag.name;
                    console.log('tag ontagadding', tag);
                    console.log('newTag  ontagadding', newTag);
                }

                datacontext.save().then(function (saveResult)
                {
                    console.log('saved tag  ontagadding');
                    if (typeof (saveResult) !== 'undefined')
                    {
                        lastSavedTag = saveResult.entities[0];
                    }
                });
            });
        }

Controller calls the service method:

function onTagAdding(tag)
        {
            dataServiceTagHelper.onTagAdding(tag);
        }

Request payload:

"entities": [{
    "Id": -1,
    "Name": "sdfsdfsdf",
    "Desc": null,
    "entityAspect": {
        "entityTypeName": "Tag:#SayusiAndo.DiLib.Model.Model.Db.Model.Blog",
        "defaultResourceName": "Tags",
        "entityState": "Added",
        "originalValuesMap": {

        },
        "autoGeneratedKey": {
            "propertyName": "Id",
            "autoGeneratedKeyType": "Identity"
        }
    }
}],
"saveOptions": {

}

Here is the full error message:

Error: [DiLib Error]  save failed!The underlying array is null.
    at createError (http://dev.dilib.local/ui/scripts/breeze.debug.js:15821:15)
    at handleHttpError (http://dev.dilib.local/ui/scripts/breeze.debug.js:15811:15)
    at Object.breeze.AbstractDataServiceAdapter.proto.saveChanges.ajaxImpl.ajax.error (http://dev.dilib.local/ui/scripts/breeze.debug.js:15687:9)
    at errorFn (http://dev.dilib.local/ui/scripts/breeze.debug.js:16026:14)
    at http://dev.dilib.local/ui/scripts/angular.js:9415:11
    at processQueue (http://dev.dilib.local/ui/scripts/angular.js:13248:27)
    at http://dev.dilib.local/ui/scripts/angular.js:13264:27
    at Scope.$get.Scope.$eval (http://dev.dilib.local/ui/scripts/angular.js:14466:28)
    at Scope.$get.Scope.$digest (http://dev.dilib.local/ui/scripts/angular.js:14282:31)
    at Scope.$get.Scope.$apply (http://dev.dilib.local/ui/scripts/angular.js:14571:24)

Server side:

StackTrace: "   at System.ArraySegment`1.System.Collections.IEnumerable.GetEnumerator()
↵   at System.Data.Entity.Core.Objects.EntityEntry.TakeSnapshotOfRelationships()
↵   at System.Data.Entity.Core.Objects.ObjectContext.AddObject(String entitySetName, Object entity)
↵   at Breeze.ContextProvider.EF6.EFContextProvider`1.AddObjectStateEntry(EFEntityInfo entityInfo)
↵   at Breeze.ContextProvider.EF6.EFContextProvider`1.ProcessEntity(EFEntityInfo entityInfo)
↵   at Breeze.ContextProvider.EF6.EFContextProvider`1.ProcessSaves(Dictionary`2 saveMap)
↵   at Breeze.ContextProvider.EF6.EFContextProvider`1.SaveChangesCore(SaveWorkState saveWorkState)
↵   at Breeze.ContextProvider.ContextProvider.OpenAndSave(SaveWorkState saveWorkState)
↵   at Breeze.ContextProvider.ContextProvider.SaveChanges(JObject saveBundle, TransactionSettings transactionSettings)
↵   at SayusiAndo.DiLib.Service.WebApi.Controllers.Breeze.DiLibController.SaveChanges(JObject saveBundle) in c:\PROJECTS\sayusiando.visualstudio.com\DiLib\Dev\branches\DiLib-Dev\src\DigitalLibrary\App\DiLib\Service\DiLib.Service.WebApi\Controllers\Breeze\DiLibController.cs:line 29
↵   at lambda_method(Closure , Object , Object[] )
↵   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass10.<GetExecutor>b__9(Object instance, Object[] methodParameters)
↵   at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(HttpControllerContext controllerContext, IDictionary`2 arguments, CancellationToken cancellationToken)
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
↵   at System.Web.Http.Controllers.ApiControllerActionInvoker.<InvokeActionAsyncCore>d__0.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
↵   at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__5.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
↵   at System.Web.Http.Filters.ActionFilterAttribute.<CallOnActionExecutedAsync>d__5.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Web.Http.Filters.ActionFilterAttribute.<ExecuteActionFilterAsyncCore>d__0.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
↵   at System.Web.Http.Controllers.ActionFilterResult.<ExecuteAsync>d__2.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
↵   at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
↵   at System.Web.Http.Controllers.ExceptionFilterResult.<ExecuteAsync>d__0.MoveNext()
↵--- End of stack trace from previous location where exception was thrown ---
↵   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
↵   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
↵   at System.Web.Http.Dispatcher.HttpControllerDispatcher.<SendAsync>d__1.MoveNext()"

Thanks for any help in advance!

Answer 1

I found it. I made two mistakes.

• when I created the C# classes for my object model I thought I need an array to store the BlogEntryTags, so I entered "array" and hit enter. Resharper tried to be helpful so it put an ArraySegment instead of List. It did not make any defect so far because I haven't use this part of the app.
• when I checked the possible issues I did not checked all the possible issues between breeze and db.

Now, it is working fine.

Here is the change: