Reported for version 9 as error
NETBEANS-1064 and marked "Resolved", it still persists for version 11. See description for NETBEANS-1064 error at
Clicking on "Take a Tour", one gets the following error if FireFox (66 now) is
the system's default browser:
"Could not access the URL through the external browser. Check the browser configuration."
A newcomer might ask himself after the error message:
"Well, do I have to modify something in the FireFox browser? But what?" So much more as there is no menu item by the name of "(Browser) Configuration".
One more sentence to the error message, that one has to go to "Tools > Options >General"
and has to modify "Web Browser" to one's system settings would prevent an unfriendly welcome to the newcomer.
Still it looks like a bug that the initial setting of <Default System Browser> does not work.