I am haveing issue creating a blog doctype in my contect after the upgrade. I am getting 

Object reference not set to an instance of an object.Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error: 

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace: 

[NullReferenceException: Object reference not set to an instance of an object.]
   umbraco.cms.businesslogic.property.Property.MakeNew(PropertyType pt, Content c, Guid versionId) +324
   umbraco.cms.businesslogic.Content.createNewVersion(DateTime versionDate) +632
   umbraco.cms.businesslogic.Content.CreateContent(ContentType ct) +217
   umbraco.cms.businesslogic.web.Document.MakeNew(String Name, DocumentType dct, User u, Int32 ParentId) +380
   umbraco.contentTasks.Save() +113
   umbraco.presentation.create.dialogHandler_temp.Create(String NodeType, Int32 TypeId, Int32 NodeId, String Text) +371
   umbraco.cms.presentation.create.controls.content.doCreation() +160
   umbraco.cms.presentation.create.controls.content.sbmt_Click(Object sender, EventArgs e) +5
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +9552602
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +103
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +35
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1724

I have updated two file in the config folder: xsltExtensions.config and restExtensions.config but it's still doen't work.