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IDProjectCategoryView StatusLast Update
0010133ardourbugspublic2026-01-21 21:26
Reportersojuzstudio Assigned To 
PrioritynormalSeveritycrashReproducibilityrandom
Status newResolutionopen 
PlatformUbuntuOSLinuxOS Version(any)
Product VersionMixbus 11.x 
Summary0010133: Crash when creating new session
DescriptionMixbus crashes when I create a new empty session while using the ALSA backend. I tried creating a session using the Pipewire/Jack option, and the creation succeeded. I also tried it with Mixbus 10, and the problem doesn’t occur there. It also doesn’t happen in Ardour 8.12.0.
Steps To ReproduceSteps to Reproduce

Open Mixbus (or Ardour) with the ALSA backend selected.

Create a new empty session.

Observe that Mixbus crashes immediately upon session creation.

Notes / Additional Info:

Creating a session with the Pipewire/Jack backend works correctly.

Using Mixbus 10 does not produce the crash.

Using Ardour 8.12.0 does not produce the crash.
Tagsalsa

Activities

x42

2026-01-21 20:53

administrator   ~0029746

I do this all the time with Mixbus and Ardour/git (rc2), so there must be something specific to your system.

Could you get a backtrace of the crash with Ardour nightly debug build (demo is fine) from https://nightly.ardour.org
see https://ardour.org/debugging_ardour

Thanks in advance.

x42

2026-01-21 20:55

administrator   ~0029747

PS. does re/moving preferences help

mv ~/.config/ardour9 ~/.config/ardour9.bak


or
mv ~/.config/mixbus11 ~/.config/mixbus11.bak

sojuzstudio

2026-01-21 21:26

reporter   ~0029748

This is on Ubuntu Studio 25.10. I wasn’t able to debug it, but when I run it from the command line, it looks like this.

sojuzstudio@sojuzstudio-System-Product-Name:/opt/Mixbus-11.2.27/bin$ ./mixbus11
Mixbus11.2.27 (built using 11.2-27-g30ded6ecf6 and GCC version 10.2.1 20210110)
Mixbus: [INFO]: Your system is configured to limit Mixbus to 524288 open files
Mixbus: [INFO]: Loading system configuration file /opt/Mixbus-11.2.27/etc/system_config
Mixbus: [INFO]: Loading user configuration file /home/sojuzstudio/.config/mixbus11/config
Mixbus: [INFO]: CPU vendor: GenuineIntel
Mixbus: [INFO]: AVX capable processor
Mixbus: [INFO]: AVX with FMA capable processor
Mixbus: [INFO]: CPU brand: Intel(R) Core(TM) i9-9900K CPU @ 3.60GHz
Mixbus: [INFO]: Using AVX and FMA optimized routines
Mixbus: [INFO]: Loading plugin meta data file /opt/Mixbus-11.2.27/share/plugin_metadata/plugin_tags
Mixbus: [INFO]: add_lrdf_data '/home/sojuzstudio/.config/mixbus11/rdf:/opt/Mixbus-11.2.27/share/rdf:/usr/local/share/ladspa/rdf:/usr/share/ladspa/rdf'
Mixbus: [INFO]: read rdf_file 'file:///opt/Mixbus-11.2.27/share/rdf/ardour-presets.n3'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/tap_reverb.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/ladspa.rdfs'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/blop.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/caps.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/swh-scales.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/ladspa-rubberband.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/swh-aux.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/tap-plugins.rdf'
Mixbus: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/swh-plugins.rdf'
Cannot install SIGPIPE error handler
Mixbus: [INFO]: Loading default ui configuration file /opt/Mixbus-11.2.27/etc/default_ui_config
Mixbus: [INFO]: Loading user ui configuration file /home/sojuzstudio/.config/mixbus11/ui_config
Mixbus: [INFO]: Loading 468 MIDI patches from /opt/Mixbus-11.2.27/share/patchfiles
Mixbus: [INFO]: Loading color file /opt/Mixbus-11.2.27/share/themes/dark-mixbus.colors
Mixbus: [INFO]: Loading ui configuration file /opt/Mixbus-11.2.27/etc/clearlooks.rc
Mixbus: [INFO]: Loading bindings from /opt/Mixbus-11.2.27/etc/ardour.keys
Loading ui configuration file /opt/Mixbus-11.2.27/etc/clearlooks.rc
ardour-request-device: Failed to acquire device: 'Audio1'
Device or resource busy

(mixbus-11.2.27:7463): Gtk-WARNING **: 23:21:40.496: Theme directory places/128 of theme ubuntustudio-dark has no size field


(mixbus-11.2.27:7463): Gtk-WARNING **: 23:21:40.497: Theme directory places/scalable of theme ubuntustudio-dark has no size field

The program 'mixbus-11.2.27' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
  (Details: serial 3878 error_code 3 request_code 38 minor_code 0)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)
sojuzstudio@sojuzstudio-System-Product-Name:/opt/Mixbus-11.2.27/bin$ ardour-request-device: watched PID no longer exists - releasing device.

Issue History

Date Modified Username Field Change
2026-01-21 20:00 sojuzstudio New Issue
2026-01-21 20:00 sojuzstudio Tag Attached: alsa
2026-01-21 20:53 x42 Note Added: 0029746
2026-01-21 20:55 x42 Note Added: 0029747
2026-01-21 21:26 sojuzstudio Note Added: 0029748