Hi,
you are sending the page up & page down keys using the global send keys event and its not working and also not showing any error that means you should check your onscreen keyboard in virtual machine. Definitely someone key should be ON there.
Please follow the below steps if your target application running inside VM :
1) In window run option type OSK and press enter.
2) Turn off all On keys.
3) Run your automation.
Regards,
Pankaj Khairnar