Hi Richard,

It looks like SEOChecker throws this error if a page is published but has an unpublished anscestor:

SEOChecker: SEOChecker: Error validating document '3986'
System.NullReferenceException: Object reference not set to an instance of an object.
   at SEOChecker.Core.Helpers.UmbracoUrlHelper.<>c.<GetPublishStateOfPath>b__0_3(<>f__AnonymousType0`2 <>h__TransparentIdentifier0)
   at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
   at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
   at SEOChecker.Core.Extensions.UmbracoExtensions.DocumentExtensions.HasUnpublishedParents(IContent document)
   at SEOChecker.Core.Extensions.UmbracoExtensions.DocumentExtensions.DetermineDocumentState(IContent doc)
   at SEOChecker.Core.Umbraco.DocumentWrappers.UmbracoDocument..ctor(IContent doc, IContextInfo info, String culture, String segment)
   at SEOChecker.Core.Repository.Umbraco.UmbracoDocumentRepository.Single(Int32 id, IContextInfo context, String culture, String segment)
   at SEOChecker.Core.Validation.DocumentValidator.Validate(Int32 documentId, IContextInfo context, String culture, Boolean validateKeyWords, String focusKeyword)
   at SEOChecker.Core.Repository.Queue.AnalyserQueueRepository.ProcessQueue(IContextInfo context)

I'm not seeing this error again when I've unpublished the child pages too.

Joe