Thanks for getting in touch!
This could happen for any number of reasons. Could you contact us directly at support@plugable.com so I can give you instructions on log gathering for analysis?
For anyone else encountering an issue like this, It looks like this customer was using a very old software package that we no longer distribute or support. Our latest software for the microscopes is always available at:
http://plugable.com/drivers/microscope
I recommend reading that entire page to fully understand the compatibility picture and be directed to the correct software package.