NTK Custom Error : RenderRazor RenderWidgetProductCategoryList Cast Error :Exception type: System.ArgumentException Message : The string argument 'connectionString' cannot be empty. Stacktrace: at Microsoft.EntityFrameworkCore.Utilities.Check.NotEmpty(String value, String parameterName) at Microsoft.EntityFrameworkCore.SqlServerDbContextOptionsExtensions.UseSqlServer(DbContextOptionsBuilder optionsBuilder, String connectionString, Action`1 sqlServerOptionsAction) at NtkCms.Server.BusinessRepository.DBBase.BaseDbContextMsSql.OnConfiguring(DbContextOptionsBuilder optionsBuilder) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.BusinessRepository\DBBase\BaseDbContextMsSql.cs:line 24 at Microsoft.EntityFrameworkCore.DbContext.get_InternalServiceProvider() at Microsoft.EntityFrameworkCore.DbContext.get_DbContextDependencies() at Microsoft.EntityFrameworkCore.DbContext.Set[TEntity]() at NtkCms.Server.BusinessRepository.Service.MsSqlUnitOfWork`1.DbSet[T]() in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.BusinessRepository\Service\MsSqlUnitOfWork.cs:line 227 at NtkCms.Server.Core.Base.ServicesBase.ServiceMsSqlBase`2.get_dbSet() in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Core.Base\ServicesBase\ServiceMsSqlBase.cs:line 41 at NtkCms.Server.Core.ModulesBase.ServicesModuleBase.CoreModuleServiceMsSqlBase`2.GetAll(FilterModelServerSide filter, Expression`1 includeFunction, TokenModel userTicket) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Core.ModulesBase\ServiceModuleBase\CoreModuleServiceMsSqlBase.cs:line 702 at NtkCms.Server.Core.ModulesBase.WrapperModuleBase.ModuleWrapperMsSqlBase`3.GetAll(FilterModelServerSide filter, Expression`1 includeFunction, TokenModel userTicket) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Core.ModulesBase\WrapperModuleBase\ModuleWrapperMsSqlBase.cs:line 433 at NtkCms.Server.Process.Soa.Base.SoaProcessBase`2.GetAll(FilterModelServerSide filter, TokenModel userTicket) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Process.Soa\Base\SoaProcessBase.cs:line 502 at NtkCms.Server.Web.MvcWidget.Modules.ModuleProduct.WidgetDependency.RenderWidgetProductCategoryList.RenderWidgetInDesigner(WidgetRenderInput RenderedWidgetInput, TokenModel usrData) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Web.MvcWidget\Modules\ModuleProduct\WidgetDependency\RenderWidgetProductCategoryList.cs:line 69 at NtkCms.Server.Web.MvcWidget.WidgetRender.RenderedWidget.RenderRazor(WidgetRenderInput inputValue, TokenModel usrData) in D:\SourceKaravi\TFSNtkCms\Ntk.Cms\NtkCms.Server.Web.MvcWidget\WidgetRender\RenderedWidget.cs:line 61 -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- -NTK- RenderClass: RenderWidgetProductCategoryList