Symptoms

Removing a step from the K2 workflow, corrupts the workflow. (Some lines are not connected to other workflow steps.)

Exception:
>Arg_NullReferenceException]
Arguments:
Debugging resource strings are unavailable. Often the key and arguments provide sufficient information to diagnose the problem. See http://go.microsoft.com/fwlink/?linkid=106663andVersion=5.1.41212.00andFile=mscorlib.dllandKey=Arg_NullReferenceException
Stack Trace:
at Sourcecode.WebDesigner.Designer.LineControl.UpdateStartStopLocations()
at Sourcecode.WebDesigner.Designer.DesignerControl.AdjustOverlappingLines()
at Sourcecode.WebDesigner.Designer.DesignerControl.RenderLines()
at Sourcecode.WebDesigner.Designer.DesignerControl.Refresh()
at Sourcecode.WebDesigner.Designer.MainApplication.StartupProcessLoaded(Object sender, EventArgs e)
at Sourcecode.WebDesigner.Designer.MainApplication.LoadProcessXml(Int32 processId, String xml, Process process, Boolean createLinkLine, Boolean loadSettings, Boolean resetLineLabelLocations)
at Sourcecode.WebDesigner.Designer.MainApplication.OnProcessXmlLoaded(LoadProcessArguments loadArguments, String result)
at Sourcecode.WebDesigner.Designer.MainApplication.c_GetProcessXMLCompleted(Object sender, GetProcessXMLCompletedEventArgs e)
at Sourcecode.WebDesigner.Designer.FrameworkInterop.FrameworkInteropSoapClient.OnGetProcessXMLCompleted(Object state)
 

Diagnoses

This was diagnosed as a bug in Appit 1.3. The issue was resolved in Appit 1.4 Update 2.
 

Resolution

After we upgraded the client environmet to Appit 1.4, they were able to delete the step in the workflow without workflow corruption.
(This update was pushed out to all Appit environments.)