Interesting event while duplicating a simple class, the World did not end when I clicked the button although I was bracing (I swallowed my coffee and put down the cup).
This behavior is usually due to either a dependency or a path change in the application when a VI is moved to a different location but could be related to a number of other issues that can be difficult to troubleshoot. A recompile of the VI hierarchy or a Mass Compile generally fixes these issues.
