Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Unable to locate metadata resource for: http://localhost:53414/api/data/ {Development}

See original GitHub issue

I’ve encountered this error recently on a test site I’ve been working on of BPP.

I tried to replicate and created a clean version cloned from the development branch as of yesterday to stage the error.

The error happens when I login to the site after creating a new datamodel in Breeze.

Here’s the full error:

blazor.server.js:19 [2020-09-20T15:19:23.687Z] Error: System.Exception: Unable to locate metadata resource for: http://localhost:53414/api/data/
 ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Breeze.Sharp.MetadataStore.UpdateStructuralTypeFromJNode(JNode jNode, Boolean isFromServer)
   at Breeze.Sharp.MetadataStore.<>c__DisplayClass53_0.<DeserializeFrom>b__2(JNode jn)
   at Breeze.Sharp.Core.EnumerableFns.ForEach[T](IEnumerable`1 items, Action`1 action)
   at Breeze.Sharp.MetadataStore.DeserializeFrom(JNode jNode, Boolean isFromServer)
   at Breeze.Sharp.MetadataStore.ImportMetadata(JNode jNode, Boolean isFromServer)
   at Breeze.Sharp.MetadataStore.ImportMetadata(String metadata, Boolean isFromServer)
   at Breeze.Sharp.MetadataStore.FetchMetadata(DataService dataService, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at Breeze.Sharp.MetadataStore.FetchMetadata(DataService dataService, CancellationToken cancellationToken)
   at Breeze.Sharp.EntityManager.FetchMetadata(CancellationToken cancellationToken, DataService dataService)
   at Breeze.Sharp.EntityManager.FetchMetadata(DataService dataService)
   at Breeze.Sharp.EntityManager.ExecuteQuery(EntityQuery query, CancellationToken cancellationToken)
   at Breeze.Sharp.EntityManager.ExecuteQuery[T](EntityQuery`1 query, CancellationToken cancellationToken)
   at BlazorBoilerplate.Shared.Services.ApiClient.GetUserProfile() in C:\*\repos\TestBreezeComplex\src\Shared\BlazorBoilerplate.Shared\Services\ApiClient.cs:line 21
   at BlazorBoilerplate.Shared.Services.AppState.GetUserProfile() in C:\*\repos\TestBreezeComplex\src\Shared\BlazorBoilerplate.Shared\Services\AppState.cs:line 62
   at BlazorBoilerplate.Theme.Material.Shared.Layouts.MainLayout.OnInitializedAsync() in C:\*\repos\TestBreezeComplex\src\Shared\Modules\BlazorBoilerplate.Theme.Material\Shared\Layouts\MainLayout.razor:line 70
   at Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
   at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle)

Here’s the changes:

DataModel: Test.cs

using BlazorBoilerplate.Infrastructure.Storage.DataInterfaces;
using BlazorBoilerplate.Shared.Dto.Db;
using Microsoft.AspNetCore.Mvc.RazorPages.Infrastructure;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Text;

namespace BlazorBoilerplate.Infrastructure.Storage.DataModels
{
    public partial class Test : IAuditable, ISoftDelete
    {
        [Key]
        public long Id { get; set; }

        public string Name { get; set; }

        public string Address1 { get; set; }
        public string Address2 { get; set; }
        public string City { get; set; }
        public string State { get; set; }
        public string Zip { get; set; }

        public Statuses RecordStatus { get; set; }
    }
}

DTO: Test.Cs

using BlazorBoilerplate.Shared.Dto.Db;
using Breeze.Sharp;
using System;
using System.Collections.Generic;
using System.Text;

namespace BlazorBoilerplate.Shared.Dto
{
    public partial class Test : BaseEntity
    {
        public Int64 Id
        {
            get { return GetValue<Int64>(); }
            set { SetValue(value); }
        }

        public String Name
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public String Address1
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public String Address2
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public String City
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public String State
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public String Zip
        {
            get { return GetValue<String>(); }
            set { SetValue(value); }
        }

        public Statuses RecordStatus
        {
            get { return GetValue<Statuses>(); }
            set { SetValue(value); }
        }

        //Add the following for the purpose of IAuditable and ISoftDelete functionality
        public Guid? CreatedById
        {
            get { return GetValue<Guid?>(); }
            set { SetValue(value); }
        }

        public DateTime CreatedOn
        {
            get { return GetValue<DateTime>(); }
            set { SetValue(value); }
        }

        public Boolean IsDeleted
        {
            get { return GetValue<Boolean>(); }
            set { SetValue(value); }
        }

        public Guid? ModifiedById
        {
            get { return GetValue<Guid?>(); }
            set { SetValue(value); }
        }

        public DateTime ModifiedOn
        {
            get { return GetValue<DateTime>(); }
            set { SetValue(value); }
        }
        public ApplicationUser CreatedBy
        {
            get { return GetValue<ApplicationUser>(); }
            set { SetValue(value); }
        }

        public ApplicationUser ModifiedBy
        {
            get { return GetValue<ApplicationUser>(); }
            set { SetValue(value); }
        }
    }
}

GlobalEnums.cs.

using System;
using System.Collections.Generic;
using System.Text;

namespace BlazorBoilerplate.Shared.Dto.Db
{
    public enum Statuses
    {
        Pending,
        Complete,
        Reviewed
    }
}

ApplicationDbContext.cs: public DbSet<Test> Tests { get; set; }

ApplicationController.cs:

        [HttpGet]
        public IQueryable<Test> Tests()
        {
            return persistenceManager.GetEntities<Test>().Include(i => i.CreatedBy).Include(i => i.ModifiedBy).OrderBy(i => i.Id);
        }

ApiClient.cs (and its reference in IApiClient.cs):

        public async Task<QueryResult<Test>> GetTests()
        {
            return await GetItems<Test>(from: "Tests", orderByDescending: i => i.CreatedOn);
        }

Thank you for all your help,

Jeff