I recently started getting an error which prevents Jack from starting via QjackCtl on the first try. It only happens when using my interface as the selected "Interface" (sound card), and not when I use my laptop's sound card. After dismissing the error, I can then start Jack normally.
This error occurs whenever I start Jack after plugging in my interface
-after a reboot
-after waking my laptop up from sleep
-after having previously used Jack with my laptop's sound card as the selected Interface
This error does not occur when none of the above apply and I have used Jack with my interface, stopped Jack, and restarted it without having changed the sound card it's set to use, including if I have unplugged the interface and plugged it back in again.
The sequence of messages is as follows:
First, an error message box pops up that says...
Could not connect to JACK server as client.
- Overall operation failed.
- Unable to connect to server.
Please check the messages window for more info
The messages tell me...
02:43:40.902 Could not connect to JACK server as client. - Overall operation failed. - Unable to connect to server. Please check the messages window for more info.
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
port created: Midi-Through:midi/playback_1
port created: Midi-Through:midi/capture_1
port created: Onyx-Producer-2-2:midi/playback_1
port created: Onyx-Producer-2-2:midi/capture_1
02:43:40.989 ALSA connection graph change.
Then, after I dismiss the error box, the messages show...
02:45:47.160 JACK is stopping...
Jack main caught signal 15
port deleted: Onyx-Producer-2-2:midi/playback_1
port deleted: Midi-Through:midi/playback_1
port deleted: Onyx-Producer-2-2:midi/capture_1
port deleted: Midi-Through:midi/capture_1
Released audio card Audio1
audio_reservation_finish
02:45:47.202 JACK was stopped
At this point I can start Jack and everything works fine.
There is only one thing I did differently on my end - not sure if it's a contributing factor or just a coincidence. I had been inputting "a2jmidid -ue" in the terminal so that QjackCtl would give proper names to entries in the Midi tab. To make this process quicker, I created a script that allowed me to just double-click a file to start a2j. I realized after doing this that, unlike when executing it in the terminal, I couldn't stop the script by simply closing the terminal. I have since deleted this script file and I assumed that rebooting my computer terminated the process, but it was my first-ever script and I actually don't know anything about that stuff.
Other than the above experiment, the only thing that would be different is regular software updates. No change to installation, equipment, or programs used.
As I said, I am able to start Jack after receiving and dismissing this error the first time around, but I would like to just be able to start it normally. Does anyone have any suggestions? I have already tried deleting jackd in /usr/bin, and also QjackCtl.conf in /home/.config/rncbc.org. Neither have helped.
system: Ubuntu Studio 22.04.1
QjackCtl version 0.9.6
My system uses Pulseaudio, but I can see in the system monitor that there are various Pipewire entries. However, nothing Pipewire on the "customer-facing" side.
