I can only run ardour with the breezy theme on fedora 26(have seen this issue on multiple distros)
Basically if you start ardour from the command line you get an endless stream of gtk-messages
Issue occurs in src compiled version and distro package version
I read that the payed versions lack this issue due to being built with patched gtk.
The demo version however will not run because it is unable to locate murrine and adwaita in theme engine module path
I have both theme engines installed
I hope I've missed something but is there anyway to get ardour to run without changing my theme?