I am having issues creating sheets in Project Navigator. Every time I go to my sheets tab I get a message that says "Cannot find the data. The sheet set may have been changed by others. Please refresh the project." I have refreshed the project, closed the project and refreshed it, closed autocad completely. I checked the .dst file and it is where it needs to be and hasnt been corrupted. I am now at a loss with this problem. I have attached a screen shot of the message. Somebody please help me get rid of this. It is very frustrating.