Sorry you're having this problem.
This is basically the complete step by step guide to troubleshooting results issues. I hope this helps!
1. Make sure you have the latest version of TorrentRover.
Click on Help -> Check for App Updates. The latest public version at the time of this post is 0.23.4.
2. Make sure you have the latest definitions
Click on Help -> Check for Definition Updates. I did just update the KickAss Torrents definition like 6 hours ago.
3. Make sure you try a test search that's sure to get results.
Use the quick search box for the test. I recommend "Ubuntu" since it's legal and gets results on all sites that I'm aware of. I just ran it and got results from all 4 sites.
4. Make sure you are using enough sites.
Go to Tools -> Preferences -> Searching (tab). There are 2 tabs here, one for the quick search box on the main window, and the other sets the defaults for the "Add Rover" window (advanced search). If you make your searches too specific, TorrentRover may filter results you would see otherwise. If you don't select a site, TorrentRover just doesn't search it.
5. Make sure you can get access to the sites with a web browser...
If you have access to these, skip to the next step.
If you don't have access to all these, you may want to use the Proxy option in Tools -> Preferences -> Advanced (tab) -> Proxy (section). Read the info in the blue info bubble, and pick a proxy option. I would recommend Preferred if some of your sites work, and Always if none work.
6. If you still don't have results, you may have a firewall, antivirus, and ISP problem.
What version of TorrentRover are you using?
What version of Windows are you using?
What antivirus and firewall programs are you using?
What country do you live in?
If nothing has worked, let me know. And if you want to, I can remotely help you out.