For some reason the RPT adapter is having trouble accessing Windowing APIs while trying to gain access to the Display of the windowing system. What OS/version are you using? Also are you running the adapter as a windows service or from the command-line?

If running as a service, go the the Windows service manager and modify the properties of the service. On the "Log On" tab select the option to "allow service to interact with desktop". Restart the service and see if it works. If not, logging on as an administrator and starting the adapter from the command-line (the doc tells you how to do this). See if it works now. If so, stop the adapter running on command-line, then modify the service Log On properties again and set the service to use the admins account information, as opposed to the "Local System account".

I've never seen this specific problem regardless of the services Log On properties, but this may related to your systems group policies. As a last resort you can run the adapter directly from the RPT workbench (also documented). I'm certain you wouldn't see this issue in when running in GUI mode.