If you happen to find Kotobee Author's window filled completely with black and not showing anything else, learn how to fix it here.

A black screen indicates most probably an incompatibility issue with your video driver. This can be resolved by updating your video driver.

A quick workaround to have Kotobee Author working immediately, is to right-click on the software icon, and select Properties.

Select the Compatibility tab and enable Run this program in compability mode for. 

In the dropdown list, select Windows 7 and hit OK.

Restart Kotobee Author. It should now open without a black screen.