Your graph looks correct.
However, I did try to provoke my own graph that looks very much like yours (I have shared that in another post dont remember which). If I somehow run the graph and it goes successful, then I change something (like the input to ‘AddSharedParameter’) and try to run it again, then I get the same error with ‘CloseDocument’. Result is that my dynamo session crashes and I have to restart Revit. I hope that @john_pierson can answer that problem.
Your problem starts however, at your reading the directory. Those files are placed in folders by the Revit installation and are most likely “write protected”, mine is… and then I get the same reading error as you. Remove their write protection and you are back in business.
If none of this helps you, then please provide your “shared parameter” file, just to verify you dont have any issues in that file.