Hi all,
the defaultVHost does not start on Wowza 4.8.5.05 (Java 9.0.4) in Virtual Host Setup manager page.
Anyone has such experience? How to debug?
Thank you very much.
Welcome to our forums @Beatrice_Miceli! 
I can share some code samples with you that may help you out. Look at page 55 here in the Engine user guide for VHost configuration samples.
https://www.wowza.com/resources/WowzaStreamingEngine_UsersGuide.pdf
Also, perhaps you saw this already but in case you didn’t:
If you still have issues, please send us a support ticket and we can work with you.