Symptoms

When attempting to browse SmartObjectd items under the SmartObjects Servers via the Context Browser in K2 Studio/K24VS an ?object reference? error is thrown, see video: http://screencast.com/t/i7UCSoPn1y

"System.NullReferenceException: Object reference not set to an instance of an object.
at SourceCode.Workflow.Common.HostedServers.SmartObjects.GetSmartObjectGuidCollectionForCategory(Int32 categoryId)
at SourceCode.Plugins.SmartObjectBrowser.Framework.ServerItem.OnLoadItems()"

 

Diagnoses

The error exception is normally due to a parent Category ID that no longer exists but still being referenced by child Category ID.

 

Resolution

To fix this, you first need to identify the missing parent category ID and the child category ID referencing it. After which you have to map the latter to a different Parent Category ID.
Please contact K2 Support for further assistance on this, if you run into a similar issue.