JACK - no realtime error with ardour

It is not a real Ardour issue, but somehow related.
I jam in guitarix, which is fine. when I start Ardour I can’t create a session. Terminal output says “no jack realtime”.
What can I do? Realtime box is checked in qjackctl.

bind txt domain [gtk2_ardour5] to /opt/Ardour-5.12.0/share/locale Ardour5.12.0 (built using 5.12 and GCC version 5.2.1 20150903) ardour: [INFO]: Your system is configured to limit Ardour to only 4096 open files ardour: [INFO]: Loading system configuration file /opt/Ardour-5.12.0/etc/system_config ardour: [INFO]: Loading user configuration file /home/sonnie/.config/ardour5/config ardour: [INFO]: CPU vendor: GenuineIntel ardour: [INFO]: AVX-capable processor ardour: [INFO]: CPU brand: Intel(R) Core(TM) i5-4690 CPU @ 3.50GHz ardour: [INFO]: Using SSE optimized routines Cannot xinstall SIGPIPE error handler ardour: [INFO]: Loading default ui configuration file /opt/Ardour-5.12.0/etc/default_ui_config ardour: [INFO]: Loading user ui configuration file /home/sonnie/.config/ardour5/ui_config Gtk-Message: Failed to load module "canberra-gtk-module" Color shuttle bg not found ardour: [INFO]: Loading color file /opt/Ardour-5.12.0/share/themes/dark-ardour.colors ardour: [INFO]: Loading ui configuration file /opt/Ardour-5.12.0/etc/clearlooks.rc ardour: [INFO]: Loading ui configuration file /opt/Ardour-5.12.0/etc/clearlooks.rc Found nothing along /home/sonnie/.config/ardour5/templates:/opt/Ardour-5.12.0/share/templates run dialog Cannot lock down 82280346 byte memory area (Cannot allocate memory) Cannot lock down 82280346 byte memory area (Cannot allocate memory) Scanning folders for bundled LV2s: /opt/Ardour-5.12.0/lib/LV2 Set cursor set to default Here are the errors associated with this failed session:

Errors/Messages:
ERROR: JACK: Cannot use real-time scheduling (RR/5)(1: Operation not permitted)
ERROR: JACK: JackClient::AcquireSelfRealTime error
ERROR: LADSPA: cannot load module “/usr/lib/ladspa/ladspa_guitarix.so” (/usr/lib/ladspa/ladspa_guitarix.so: undefined symbol: _ZN4Glib10Dispatcher7connectEON4sigc4slotIvNS1_3nilES3_S3_S3_S3_S3_S3_EE)
INFO: Loading bindings from /opt/Ardour-5.12.0/etc/ardour.keys
harvid version: 802
INFO: Loading menus from /opt/Ardour-5.12.0/etc/ardour.menus
ERROR: JACK: Cannot create thread res = 1


run dialog
Cannot get session parameters.

http://jackaudio.org/faq/linux_rt_config.html

Thanks. It worked. Interesting, I’d neither to add myself to the realtime group nor edit a file ever before. Ubuntu 18.04 is really interesting.