Sometimes, because of compatibility issues, you may not be able to scan with your IRIScan Mouse. It's very likely that it is a software related issue. To be sure about that, we'd recommend to follow these steps :

1. Make sure that you did download the latest version of the software : Click here
2. Make also sure that your Windows is up to date. Here is an article from Microsoft Support to know if that's the case : Click here
3. Make sure to start the software as administrator. To do so, right click on IRIScan Mouse software and select "Run as administrator" in the prompt menu.