I'm trying to add a new page/entity similar to the "Addresses" in the customer page, but I keep getting this error, I searched around for days and tried to solve it, yet zero solutions found.
So please help me solve this issue.
The stack trace is below:
System.InvalidOperationException
HResult=0x80131509
Message=Navigation property 'copyOfAddress' on entity type 'Customer' is not virtual. UseLazyLoadingProxies requires all entity types to be public, unsealed, have virtual navigation properties, and have a public or protected constructor.
Source=Microsoft.EntityFrameworkCore.Proxies
StackTrace:
at Microsoft.EntityFrameworkCore.Proxies.Internal.ProxyBindingRewriter.Apply(InternalModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnModelBuilt(InternalModelBuilder modelBuilder)
at Microsoft.EntityFrameworkCore.ModelBuilder.FinalizeModel()
at System.Lazy`1.ViaFactory(LazyThreadSafetyMode mode)
at System.Lazy`1.ExecutionAndPublication(LazyHelper executionAndPublication, Boolean useDefaultConstructor)
at System.Lazy`1.CreateValue()
at Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
at Microsoft.EntityFrameworkCore.Internal.DbContextServices.get_Model()
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetRequiredService[T](IServiceProvider provider)
at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider()
at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies()
at Microsoft.EntityFrameworkCore.DbContext.Set[TEntity]()
at Nop.Data.NopObjectContext.Set[TEntity]() in D:\nopCommerce_4.20_Source\src\Libraries\Nop.Data\NopObjectContext.cs:line 83
at Nop.Data.EfRepository`1.get_Entities() in D:\nopCommerce_4.20_Source\src\Libraries\Nop.Data\EfRepository.cs:line 236
at Nop.Data.EfRepository`1.get_Table() in D:\nopCommerce_4.20_Source\src\Libraries\Nop.Data\EfRepository.cs:line 221
at Nop.Services.Tasks.ScheduleTaskService.GetAllTasks(Boolean showHidden) in D:\nopCommerce_4.20_Source\src\Libraries\Nop.Services\Tasks\ScheduleTaskService.cs:line 81
at Nop.Services.Tasks.TaskManager.Initialize() in D:\nopCommerce_4.20_Source\src\Libraries\Nop.Services\Tasks\TaskManager.cs:line 39
at Nop.Web.Framework.Infrastructure.Extensions.ServiceCollectionExtensions.ConfigureApplicationServices(IServiceCollection services, IConfiguration configuration, IHostingEnvironment hostingEnvironment) in D:\nopCommerce_4.20_Source\src\Presentation\Nop.Web.Framework\Infrastructure\Extensions\ServiceCollectionExtensions.cs:line 90
at Nop.Web.Startup.ConfigureServices(IServiceCollection services) in D:\nopCommerce_4.20_Source\src\Presentation\Nop.Web\Startup.cs:line 38
This exception was originally thrown at this call stack:
Microsoft.EntityFrameworkCore.Proxies.Internal.ProxyBindingRewriter.Apply(Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder)
Microsoft.EntityFrameworkCore.Metadata.Conventions.Internal.ConventionDispatcher.ImmediateConventionScope.OnModelBuilt(Microsoft.EntityFrameworkCore.Metadata.Internal.InternalModelBuilder)
Microsoft.EntityFrameworkCore.ModelBuilder.FinalizeModel()
System.Lazy<T>.ViaFactory(System.Threading.LazyThreadSafetyMode)
System.Lazy<T>.ExecutionAndPublication(System.LazyHelper, bool)
System.Lazy<T>.CreateValue()
Microsoft.EntityFrameworkCore.Internal.DbContextServices.CreateModel()
Microsoft.EntityFrameworkCore.Internal.DbContextServices.Model.get()
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(Microsoft.Extensions.DependencyInjection.ServiceLookup.ScopedCallSite, Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope)
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(Microsoft.Extensions.DependencyInjection.ServiceLookup.ConstructorCallSite, Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope)
...
[Call Stack Truncated]