I keep getting this error message when trying to show a chart in certain studies.  Once I start getting the error, it won't go away for that study.  Sometimes if I delete the study and start over it fixes the problem.  I'd like to know what the root cause is so I can avoid this in the future.  The results  (CWR) file is present and of decent size.  I'm using SolidWorks 2009 SP3.  Thanks for any insight.