I have the same problem. Does anyone know solution?
Could be a number of reasons. Maybe inconsisten data in EPiServer database?
But first check that EPiServer User Interface files are in sync with binaries - so the apx/ascx files are matching the dlls in your project.
More clues are needed to provide a better answer!
Hook up the debugger and follow these instructions:
In this case it would be valuable with information on all local varibles but also the values of the object.
Thank you for your reply, Fredrik.
I think the problem is in inconsistent data in DB. We have moved to newer version of EPiServer and probably were not good at it.
Thank you. this was very helpful!
Got this error today when upgraded and the solution is simple: have a look in your web.config file and you will find that you are probably missing the virtual path for UI folder. Also if you have made an upgrade from an early epi-version you probably have episerverspecific folders in you wwwroot-folder. Delete them and ad the virtual path for the UI folder and you have solvde the issue :) if this is not working you are probably having some databaseissues.
<add name="UI" virtualPath="~/cms/" physicalPath="C:\Program Files\EPiServer\CMS\5.2.375.236\application\UI" type="EPiServer.Web.Hosting.VirtualPathNonUnifiedProvider,EPiServer" />
I get this an nullReferenceExeption when i try to add or edit propertys to a page type.
Has anyone experienced the same problem?
[NullReferenceException: Object reference not set to an instance of an object.]
EPiServer.UI.Admin.EditPageTypeField.OnLoad(EventArgs e) +507
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2427