Hi Folks

Currently I'm getting the following error after an upgrade of Umbraco 4.7.2 to 4.11.1 - I know that applicationbase is deprecated but I believe it should still work or?

When I'm saving a certain document type there is some code that hooks in to the BeforeSave event - this used to be working on 4.7.2....

Does anyone have a clue about what is going on and if it can easily be fixed without having to refactor the code?

Value cannot be null.

Parameter name: attribute

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.ArgumentNullException: Value cannot be null.

Parameter name: attribute

Source Error: 

Line 126:                        sender.Save();

Line 127:                        //Make sure the node is refreshed in backoffice

Line 128:                        umbraco.library.UpdateDocumentCache(sender.Id);

Line 129:                        umbraco.library.RefreshContent();

Line 130:                        umbraco.BasePages.BasePage.Current.ClientTools.SyncTree(sender.Path, true);

Source File: D:\data\project\website.Backend\AdminSaveHandlers.cs    Line: 128 

Stack Trace: 

[ArgumentNullException: Value cannot be null.

Parameter name: attribute]

   System.Xml.Linq.XAttribute.op_Explicit(XAttribute attribute) +91251

   UmbracoExamine.UmbracoContentIndexer.ReIndexNode(XElement node, String type) +110

   Examine.ExamineManager._ReIndexNode(XElement node, String type, IEnumerable`1 providers) +81

   UmbracoExamine.UmbracoEventManager.content_AfterUpdateDocumentCache(Document sender, DocumentCacheEventArgs e) +182

   umbraco.DocumentCacheEventHandler.Invoke(Document sender, DocumentCacheEventArgs e) +0

   umbraco.content.FireAfterUpdateDocumentCache(Document sender, DocumentCacheEventArgs e) +26

   umbraco.content.UpdateDocumentCache(Document d) +717

   umbraco.library.UpdateDocumentCache(Document doc) +107

   umbraco.library.UpdateDocumentCache(Int32 documentId) +45

   website.Backend.AdminSaveHandlers.NyhedSave(Document sender) in D:\data\project\website.Backend\AdminSaveHandlers.cs:128

   website.Backend.AdminSaveHandlers.Document_AfterSave(Document sender, SaveEventArgs e) in D:\data\project\website.Backend\AdminSaveHandlers.cs:34

   umbraco.cms.businesslogic.web.SaveEventHandler.Invoke(Document sender, SaveEventArgs e) +0

   umbraco.cms.businesslogic.web.Document.FireAfterSave(SaveEventArgs e) +27

   umbraco.cms.businesslogic.web.Document.Save() +180

   umbraco.cms.presentation.editContent.Save(Object sender, EventArgs e) +1951

   System.EventHandler.Invoke(Object sender, EventArgs e) +0

   umbraco.controls.ContentControl.saveClick(Object Sender, ImageClickEventArgs e) +319

   umbraco.controls.ContentControl.savePublish(Object Sender, ImageClickEventArgs e) +20

   System.Web.UI.WebControls.ImageButton.OnClick(ImageClickEventArgs e) +115