Hello Abel.
Thank you for helping. I solved the issue. In case someone undergoes the same problem this is the solution
Situation
It seems jdk does no longer work with ant.
So this is what I did to make my jar
1. right click on the project
2. chose "Export" in the menu
3. In the opening window chose Java and then "Runnable Jar file" => Next
4. There are 3 options , I chosed the 2 nd "package required libraries in the generated Jar"
=> The Jar I got works very well but the installer from it won't work.
The solution is to change step 4.
Chose copy required libraries into a sub-folder next to the generated JAR instead
After that the JAR works and the exe installer gives a working application.
I hope it helps someone out there.