“Object reference not set to an instance of an object”-exception on mobile sharepoint page

Question

My Situation:

When I try to access the (custom) masterpage of a SharePoint 2010 solution, I'm developing, in the mobile view (using the Microsoft Mobile Device Emulator /w Win Mobile 6.1/IE6) I get the "Object reference not set to an instance of an object" exception without further explanation. The error is shown directly on the page itself.

The log on the server shows no error(s), and since I haven't developed any custom mobile sites or webparts yet and the normal Master-page in IE8 shows no errors I literally have not the slightest clue what's causing the error, and I see no mean how to debug this...

This is pretty much a deadlock for me, and this gives me serious headaches cause it's the first time for me to work with the built-in SharePoint mobile-view thing and I really don't now what to do to get beyond this to actually start working.

I hope that this describes my problem well enough, otherwise I'll try to provide you with further information. (Just let me know)

I'm aware that it is probably hard to help me in this special use-case because there is no error-source known yet. But I'm thankful for every answer and comment that can point in the right direction to solve this problem and/or to get the source of this error.

sincerely, Markus Schwalbe

---

EDIT: as requested, here's the stack trace:

bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateChildControlsFromXmlNode(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateStyleChildControl(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateChildControlsFromXmlNode(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateStyleChildControl(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateChildControlsFromXmlNode(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateStyleChildControl(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateChildControlsFromXmlNode(XmlNode node, ControlCollection controls)
bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.CreateChildControlsForWiki(SPListItem item) bei Microsoft.SharePoint.MobileControls.SPMobileWikiPage.OnLoad(EventArgs e) bei ASP._layouts_mobile_mblwiki_aspx.OnLoad(EventArgs e) in c:\\Program Files\\Common Files\\Microsoft Shared\\Web Server Extensions\\14\\TEMPLATE\\LAYOUTS\\MOBILE\\mblwiki.aspx:Zeile 13. bei System.Web.UI.Control.LoadRecursive() bei System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I hope that helps. btw. editing the web.config to show the stack trace didn't worked out, but I managed to debug the mblwiki.aspx, and found out that the exception is thrown in the onLoad() method: (I got the stack trace from there)

http://img18.imageshack.us/img18/3350/errorub.jpg << It's a link, because stackoverflow doesn't allows me to post images directly. (my rep is still too low)

Also a note to the image (Since it's in german): "Der Objektverweis wurde nicht auf eine Objektinstanz festgelegt." == "Object reference not set to an instance of an object."

Answer 1

I got the solution... kinda...

I deleted the site-collection in question. And rebuilt the whole thing. To cut a long story short, it works now, even thought it's the same as before. The same websites, the same content-types, design and webparts (etc.). The reason for the error remains unknown, but now it works and I'm half-satisfied at least.

If i learned jsut one thing about this problem, than it's: "Don't question all the things that makes no sense, it's a huge waste of time. Just try to don't repeat the same mistakes ever again".

I leave this topic with this statement and hope you (who ever reads this) doesn't get the same error.

---

by the way: It's always good to try to reproduce your error if you can't pin it down directly!