The problem is usually related to a faulty driver installation.
For a successful driver installation, you should first pay attention to the following aspects:

• Before you start recording, unplug all USB devices from your computer which are not needed for the recording (except for your keyboard and mouse) to avoid any device conflicts.
• Try using a different USB port on your computer for analog recordings. 
• Do not use a USB hub. 
• Connect the USB video converter directly to your computer (do not use a USB extension cable). 
• If you have been using the USB ports on the front of your PC until now, try connecting the video converter to one of the ports on the back.
• Download and install the latest drivers for your USB video converter.

Video Converter (Model: Black)
Video Converter (Model: Red)
Video Converter (Model: Premium) 

Now follow the steps below to install your device drivers:

1. Save the archive to your PC, then extract the contents of the archive to a folder on your PC.
2. Before installing the drivers, pause all security programs on your PC (firewall, antivirus).
3. Run "setup.exe" from the extracted folder. If drivers are already installed on your PC, select "Remove" and restart the installation.
4. Run the program as administrator and reset its settings to their defaults. To do this, go to "File" > "Settings..." and select "Reset program settings to defaults".
5. Try to capture the video again.

If the problem persists, please read the following article:
"My capture devices cannot be recognized"