Are you getting a "The root activity type is invalid" error with the Custom Activity Designer sample?

Several peolple have gotten a “The root activity type is invalid” error when using the Custom Activity Designer sample that can be found at http://wf.netfx3.com/files/folders/activity_behavior/entry840.aspx.  I created an update project that should resolve the problem, which can be downloaded from the link below. FlowChart.zip

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