2019-09-24 13:22:23.204: Running.
2019-09-24 13:22:23.219: Fetching build definition.
2019-09-24 13:22:23.219: Fetched build definition. 'Dynamicweb.Content.ContentIndexBuilder'.
2019-09-24 13:22:23.219: Preparing schema.
2019-09-24 13:22:23.219: Prepared schema.
2019-09-24 13:22:23.219: Creating index writer.
2019-09-24 13:22:23.282: Created index writer: 'Dynamicweb.Indexing.Lucene.LuceneIndexWriter'.
2019-09-24 13:22:23.297: Instance availability (ContentIndex): False.
2019-09-24 13:22:23.297: Starting build process.
2019-09-24 13:22:34.579: BuildIndex failed.. System.NullReferenceException: Object reference not set to an instance of an object.    at Dna.Winnebago.IndexBuilderExtender.ContentIndexBuilderExtender.GetHeadingContentItemFields(List`1& headingField, List`1& contentField, Int32 itemListId, String headingColumn, String contentColumn)    at Dna.Winnebago.IndexBuilderExtender.ContentIndexBuilderExtender.ExtendDocument(IndexDocument doc)    at Dynamicweb.Content.ContentIndexBuilder.WriteDocument(IndexDocument document, Int32 pageId, IIndexWriter writer, Tracker tracker)    at Dynamicweb.Content.ContentIndexBuilder.BuildContent(IIndexWriter writer, Tracker tracker)    at Dynamicweb.Content.ContentIndexBuilder.Build(IIndexWriter writer, Tracker tracker)    at Dynamicweb.Indexing.Index.Build(String instance, String name, Tracker tracker)    at Dynamicweb.Indexing.IndexService.<>c__DisplayClass14_0.<BuildIndex>b__0(Tracker tracker)
2019-09-24 13:22:34.579: BuildIndex failed.
2019-09-24 13:22:34.766: Failed (1540 / 1560).