If the record function is producing empty files (i.e. files that are only 0 kB in size), this is likely because the sound is not being recorded along with the picture. In most cases, this problem can be fixed by switching the audio driver. 

But before switching the driver, try the following:

• Right-click the program .exe file and run the program as an administrator. 
• Reset the program to its default settings. 
  To do this, go to "File" > "Settings..." > "Reset program settings to defaults".
• Check to make sure you are using the latest version of the program. To check for available updates, go to "Update online" in the Help menu.

To change the audio driver, follow these steps: 

1. Open the "Advanced view". 
2. Under "Audio device", select any driver (device) other than the one currently selected .
3. Then, reselect the MAGIX USB video converter. 
   The name of the driver should correspond to the version of the converter you are using (e.g. "USB 2861 Device" or "USB 2828 Device"). 

The USB video converter should now be "active", and you should be able to record normally.
If the recording still doesn't work, set the recording quality from "Very high" to "High" and try again. In the record dialog, enable "Automatic scene recognition" (bottom right, above "Start video editing").