UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3378.0 Safari/537.36

Steps to reproduce the problem:
1. Open the page https://docs.oracle.com/javase/tutorial/deployment/webstart/deploying.html
2. Press the "Launch" button
3. Try to keep and launch the downloaded file "dynamictree_webstart.jnlp"

What is the expected behavior?

What went wrong?
There is no way to keep the jnlp file (and then launch it).

Did this work before? Yes 

Chrome version: 67.0.3378.0  Channel: n/a
OS Version: OS X 10.13.3
Flash Version: 

The issue doesn't occur in the Windows version.