System.NullReferenceException: Object reference not set to an instance of an object. at EscoraLN.Services.CCoursesServicePub.GetCourseAsync(String CourseID) in D:\Prog\EscoraLN\Services\Pub\CCoursesServicePub.cs:line 141 at EscoraPub.Components.Courses.Attendees.Attendees.OnParametersSetAsync() in D:\Prog\EscoraPub\Components\Courses\Attendees\Attendees.razor.cs:line 30