Opening a WF4 workflow in xaml editor. you can find that sad:XamlDebuggerXmlReader.Filename attribute point to a physical file path. What a mysterious physical path.
Why do we need this attribute? this attribute is used for WF4 workflow debugging. VS debugger will find the break point code line in the file base on this file path.
What this problem: if we move this xaml workflow to another computer, and then you will get error message if you debug it there.
Should we delete this file path? we'd better not delete this.
What should we do then? When we are going to create a workflow we'd better create and debug the workflow in the same computer.