WPF-Browserapplication are not run in the Firefox, but in IE

Question

Hello!

I'm from germany and this is my first Question at C#Corner.

I have a problem with my WPF-Browserapplication.

 

The Firefox don't start the application, what can I do?

I have read, the firefox has an add-on, but I can't find it!

 

The picture shows what the firefox mean, when i will load the application

 

 

 

I hope you can help me!

 

Thank you Marcus