Oh, that is bad and something is really wrong. Make sure you downloaded and extracted mission editor folder containing all necessary libraries to your local drive. Download link is here:
WOFF UE Mission editor
Than download the latest executable and place it to folder created in previous step. Download it here:
WOFF UE Mission editor.jar
Run WOFF UE Mission_editor.jar - the latest, v1.0.4. You must be connected to internet to see the map. Without internet connection you get only black background.
When you clik Show enemy flights checkbox, you must choose if you want to see waypoints or not. Than you must click the Next formation button several times to the point where enemy flights are stored.
Let me know if you have still difficulties.