NullReferenceException after deactivating and deleting a webtemplate from solutions

Question

After deactivating and deleting a web template that was not in use I am receiving null reference exceptions when trying to view Site Settings >> Solutions or any page that is not on the root.

In the ULS Viewer I am seeing the following: [NullReferenceException: Object reference not set to an instance of an object.] Microsoft.SharePoint.WebPartPages.ListViewWebPart.PrepareContentTypeFilter(SPList list, Hashtable[] excludedTransformers) +176 Microsoft.SharePoint.WebPartPages.ListViewWebPart.GenerateDocConvScriptBlock(SPWeb web, SPList list) +482 Microsoft.SharePoint.WebPartPages.ListViewWebPart.OnPreRender(EventArgs e) +1957 Microsoft.SharePoint.WebPartPages.WebPartMobileAdapter.OnPreRender(EventArgs e) +78 System.Web.UI.Control.PreRenderRecursiveInternal() +11032094 System.Web.UI.Control.PreRenderRecursiveInternal() +223 System.Web.UI.Control.PreRenderRecursiveInternal() +223 System.Web.UI.Control.PreRenderRecursiveInternal() +223 System.Web.UI.Control.PreRenderRecursiveInternal() +223 System.Web.UI.Control.PreRenderRecursiveInternal() +223 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3393

I have done this same action 1000 times, and until today never had this issue. If I delete the site and rebuild everything it works, however, I need to fix this issue so I can save my work.

Does anyone know what the issue could be?

Answer 1

I did not ever figure out how to recover from this error. However, I worked around it be re-creating the site using the template I had prior >> reworking my changes >> instead of de-activating the template, i resaved creating a new one. The following link discusses the same issue more thoroughly:

http://www.thorprojects.com/blog/archive/2010/05/02/don%E2%80%99t-deactivate-that-site-template-solution.aspx

The lesson I took from this, is to be very cautious before de-activating a template that was used to build your root site. I won't mark this as the answer to the issue. The purpose is to only serve as a warning to others.