Hi Mike,
When you generate a report in SAM, it creates and saves a PDF file on your computer, and then tries to open it with whatever application on your computer is set to open PDF files by default. That error message means that SAM could not open the PDF file for some reason, but you should still be able to find the file and open it yourself.
One possible cause of the error is that the .pdf file extension is not associated with an application on your computer.
Could you email me a screenshot of the actual error so we can see the full path?
Best regards,
Paul.