Ardour crashes on startup from bad plugins

Issue 1:
Ardour (v5.3.0) crashes upon launching certain sessions. The crashes appear to be caused by “bad plugins” as launching Ardour by navigating to its /bin folder in the terminal and running “./ardour5 -B” to bypass plugins allows it to successfully launch. This occurs on AV Linux, but also occurred on Ubuntu 16 with Ardour 4 installed. The sessions were originally recorded with Ardour4. Ardour5 still crashes when the “Safe Mode” checkbox is checked.

Issue 2:
When running with the “-B” predicate the playback is still “messed up.” It is slow, has pops and static. Removing (deleting) all plugins does not fix the issue. The application also experiences general slowness in affected sessions: scrolling, loading, operations.

Issue 3:
I have copied sessions affected by these issues into a new directory (say “cp -r Session1 Session2”) giving write permissions only to root. When launching outside of root, Ardour launches in “Read Only Mode.” In Read Only Mode the playback is “correct” (no pops, static, general distortion) but I of course can not save any changes.

Issue 4:
When all plugins are deleted in a session, the session is “Saved As” and reopened the playback will be “correct.” However as soon as a plugin is added back in the playback is again “messed up.”

It seems any plugin being added causes these issues to the affected sessions. I am mostly using Guitarix LV2 plugins, all plugins are LV2. I think the issues are caused by too many regions in the sessions, or rather recording too many regions. The affected sessions have 100+ regions across several tracks as a result of me messing around for a while whilst learning Ardour. Clicking “Clean Unused Regions” in the Region List does not solve the issue.

I would like to:

  1. Salvage these sessions: get the audio and MIDI tracks into a new, usable session or make the affected sessions “work.”
  2. Learn what is causing this issue and how to avoid it in the future.

for crashes:

You will need a debug build, easiest obtained from


I have personally had a lot of problems with Guitarix Amplifier-X and Mixbus sessions, to be fair since I’ve seen this issue I’ve avoided that particular plugin with Ardour sessions but it wouldn’t surprise me if it affects one it may affect the other. What is puzzling is during the session the plugin works perfectly and doesn’t cause any trouble but when you try and re-open the session it will fail.

In my experience this has been with 32bit, rthomaskelly are you using 32bit AV Linux?

I’m running 64bit AV/L. Have you happened to notice if the Amplifier-X-Stereo causes the same problem? I tried testing it but as I described Ardour only seems to crash for larger sessions and all of mine are currently hosed.

I see now there is already a bug report for this:


I’ve only noticed this on my production machine which is 32bit for now, I haven’t tested it on 64bit. I’ve mentioned it on the IRC channel in the past and nobody was able to reproduce it on 64bit but it was a very brief discussion and not a very thorough test.

I’ve had a few sessions crash on startup, at least since some version 4.x, but never really investigated it. I did notice that (all of?) the sessions that crash seemed to use Guitarix plugins. After removing the Guitarix plugins in safe mode the sessions load again (leaving all other plugins active). I’m also seeing that new instances of Guitarix plugins work great until you reload the session. I’m on 64bit Arch.