Sometimes it can be helpful to reset SilverFast to the factory default settings.
A word of caution:
Resetting SilverFast to factory defaults will not only reset the software, but will also delete your SilverFast preferences including saved settings.
Please start SilverFast from the welcome screen and click on the Service-tab.
In the service-tab please click on the rectangle button "Software Reset".
After you've clicked on the button, a confirmation dialogue will appear that the reset was successful.
You're done. The software is now in a state as if it was just freshly installed.
Here's a legacy movie on how to reset SilverFast in version 8 to factory settings, basically the same procedure as in current SilverFast 9 version, but the interface is a little bit different.