Hi 

after upgrading from 4.11.3 to 6.0 I get lots of these in my log

2013-02-19 20:03:10,194 [25] DEBUG umbraco.content - [Thread 33] Xml saved in 00:00:00.0225516
2013-02-19 20:03:10,225 [25] INFO  Umbraco.Core.Services.ContentService - [Thread 36] Content '8.-9. september' with Id '5147' could not be published because of invalid properties.
2013-02-19 20:03:10,225 [25] INFO  umbraco.BusinessLogic.Log - [Thread 10] Redirected log call (please use Umbraco.Core.Logging.LogHelper instead of umbraco.BusinessLogic.Log) | Type: Custom | User: 0 | NodeId: 5138 | Comment: [UmbracoExamine] (ExternalIndexer)Field "ExternalIndexSet" is listed multiple times in the index set "sortOrder". Please ensure all names are unique
2013-02-19 20:03:10,272 [25] ERROR umbraco.content - [Thread 36] Error adding node to Sitemap Provider in PublishNodeDo(): 5147
System.ArgumentNullException: Value cannot be null.
Parameter name: umbracoContext
   at Umbraco.Web.UmbracoHelper..ctor(UmbracoContext umbracoContext)
   at umbraco.content.PublishNodeDo(Document d, XmlDocument xmlContentCopy, Boolean updateSitemapProvider)

and it eats my sitet slowly since all pages get damaged. I have compared all my files with a fresh local version

Any suggestions

/Paul S