Just want to report my findings and actions.
When I logged in as another user the fontsetting worked so obviously something happened to my user profile.
Searched long but could not find what it was so I deleted my user profile including all data. Restarted the computer and made a new user profile.
In this new profile the font setting works.
It is a drastic measure and a lot of settings etc. have to be made again. But at least e-Sword has a good font again.
Strange that no other programs were affected.
/Kjell aka Kamau