System.NullReferenceException: Object reference not set to an instance of an object. at Vivace.Library.Cms.Factories.PublishedPageFactory.Convert(IAssignment assignment, DisplayContextType displayContextType, String parentId, String displayParentId) in D:\Accelerate Education\build\git\vivace\Vivace.Solution\Vivace.Library\Cms\Factories\PublishedPageFactory.cs:line 468 at Vivace.Library.Cms.Factories.PublishedPageFactory.GetPublishedPageForLearningObject(Site site, String lessonId, String learningObjectId, String pageId, DisplayContextType displayContextType, IEnumerable`1 formatives, UrlBundle bundle, StrandType strand, Nullable`1 workflow) in D:\Accelerate Education\build\git\vivace\Vivace.Solution\Vivace.Library\Cms\Factories\PublishedPageFactory.cs:line 148 at Vivace.Cms.Controllers.LearningObjectController.CreatePublishedPageModel(String learningObjectId, String pageId, String bundle, String templateAbbreviation, String strandAbbreviation) in D:\Accelerate Education\build\git\vivace\Vivace.Solution\Vivace.Cms\Controllers\LearningObjectController.cs:line 1768 at Vivace.Cms.Controllers.LearningObjectController.PubLearningObjectPageWithTemplate(String bundle, String templateAbbreviation, String learningObjectId, String pageId) in D:\Accelerate Education\build\git\vivace\Vivace.Solution\Vivace.Cms\Controllers\LearningObjectController.cs:line 191