Try not work with jackdbus from qjacktl: turn off Setup/Misc/Other/Enable JACK D-Bus interface; killall jackd that might be possibly running; killall jackdbus as well; start qjackctl and try now again.
Also look for some error our suspicious evidences on the messages window
One question though: where did you get that newer qjackctl v0.4.5 from? Is that from regular ubuntu16.04 universe?
byee
Try not work with jackdbus from qjacktl: turn off Setup/Misc/Other/Enable JACK D-Bus interface; killall jackd that might be possibly running; killall jackdbus as well; start qjackctl and try now again.
Also look for some error our suspicious evidences on the messages window
One question though: where did you get that newer qjackctl v0.4.5 from? Is that from regular ubuntu16.04 universe?
byee