System Freezes when opening Editor

I have been adding audio to a video with Ardour on Ubuntu. At one point during the edit, I think I may have hit a wrong hotkey or something. The timeline got messed up and stretched into something much, much longer than the actual project. Then Ardour became unresponsive and I forced it to quit.

Now, when I try to open the Ardour session, it runs normally until I enter the editor. When I do, I have a few seconds to force-quit Ardour, or else my entire system will freeze and I have to do a hard reset.

I have the project file that’s causing the problem if anyone would like to see it.

Anyone have a clue how this is possible? Did I do something wrong? I’m new to Ubuntu and I’ve never had any serious problems using Ardour on Windows.


Using i9 9900K 3.60 ghz processor
nVidia gtx 1080
Behringer UMC404HD USB audio interface
Ubuntu says it is up to date.
Ardour has a cryptic popup about some sort of memory limit.
Ubuntu is version 18.04.3 LTS

Perhaps an invalid zoom-level? We’ve seen issues in the past where Ardour 5.x calculates a music-time grid until the sun turns nova… but usually runs out of memory before that :slight_smile:

In the session-folder, try moving the “instant.xml” file away (or delete it).
That file only contains Editor-settings (zoom-level, window-size and position, etc). It is save to be removed.

It might also be helpful to start Ardour from a terminal. There may be some abort message printed there.

That did seem to do something. Now, it opened normally, and crashed only when I zoomed out. There’s a weird bug where, when I try to ctrl-scroll wheel to zoom in the editor widow, it zooms to a single sample and won’t zoom out unless I hover my mouse over the navigator in the bottom of the screen. I didn’t mention it before because I didn’t think it could be related.
konkor GNOME cpufreq turned red and said ‘System overload’ when this happened.

Anyways, no system freeze this time. This should be sufficient to at least recover my work.

Here was the contents of instant.xml:

<?xml version="1.0" encoding="UTF-8"?>
  <Main x="67" y="27" w="1035" h="1020" current-tab="mixer"/>
  <Mixer mixer-rhs-pane1-pos="0.60000002384185791" mixer-rhs_pane2-pos="0.69999998807907104" mixer-list-hpane-pos="0.20000000298023224" mixer-inner-pane-pos="0.80000001192092896" narrow-strips="0" show-mixer="0" show-mixer-list="1" maximised="0" monitor-section-visible="0">
    <Window name="Mixer" visible="0" x-off="-1" y-off="-1" x-size="-1" y-size="-1" tabbed="1"/>
    <Window name="Preferences" visible="0" x-off="-1" y-off="-1" x-size="-1" y-size="-1" tabbed="1"/>
  <Meterbridge show-meterbridge="0">
    <geometry x-size="600" y-size="400" x-pos="1" y-pos="1"/>
  <Editor id="41" edit-horizontal-pane-pos="0.89999997615814209" notebook-shrunk="0" edit-vertical-pane-pos="0.89999997615814209" mixer-width="Wide" zoom-focus="ZoomFocusPlayhead" zoom="1" snap-to="SnapToBeat" snap-mode="SnapOff" internal-snap-to="SnapToBeat" internal-snap-mode="SnapOff" pre-internal-snap-to="SnapToBeat" pre-internal-snap-mode="SnapOff" edit-point="EditAtMouse" visible-track-count="-1" playhead="784188" left-frame="9223372036854080512" y-origin="0" show-measures="1" maximised="0" follow-playhead="0" stationary-playhead="0" region-list-sort-type="ByEndInFile" mouse-mode="MouseObject" join-object-range="0" show-editor-mixer="0" show-editor-list="0" editor-list-page="1" show-marker-lines="0" nudge-clock-value="240000">
    <Window name="Editor" visible="0" x-off="-1" y-off="-1" x-size="-1" y-size="-1" tabbed="1"/>
    <RegionList sort-type="ByEndInFile" sort-ascending="1" show-all="0" show-automatic-regions="1"/>
    <ActionScript lua="Lua 5.3">c2NyaXB0cyA9IHt9IA==</ActionScript>
    <EditorLocations clock-mode="BBT"/>
  <LastUsedSnapshot name="octopus_session1_ardour"/>

Is there anything I can do to help identify and fix the error? It will help me learn more about Linux while also helping you.

In the meantime- I’m also getting a message about IRQ Balance. I’m going to try to uninstall this and see if it is related. I’m using cpufreq because Ardour gave me a message about CPU governors while installing. cpufreq allows me to set it to performance, as the installer said to do.

Also, just noticed this in the console:
Segmentation Fault (core dumped)

In the instant XML there’s

Now that certainly explains it.

Show 1 sample per pixel staring at about 6 million years (!) into the session (assuming a sample-rate of 48k – 9223372036854080512 / 48000 / 86400 / 365 = 6093150)

That certainly explains the crash. Could it be that session start/end markers are off for some reason? Can you zoom-to-session?

Now that I’ve deleted the instant.xml, zoom-to-session works normally. The yellow ‘end’ flag is still astronomically far away. Clicking on this causes Ardour to freeze, but not the system anymore. I think I can figure out how to reset it to a reasonable value. But why does this happen to begin with? Can I change a preference to fix the zoom behavior?

Anyways, I’d like to avoid trying to use the old crashing file if possible since I don’t think it’s good for my PC to hard-crash like that, but I’ll do it if you tell me to.

The ulimit memory limit thing seems to be limiting Ardour to 16GB of RAM.

I remember the editor suddenly zooming out to encompass the whole enourmous range after accidentally pressing a wrong key somewhere in the middle of the keyboard. I don’t know if I set the end that way, or if it was set to a huge number somehow without me knowing it and all I did was zoom to fit the range.

I think it might have defaulted to this value, or taken the value when I imported the video into the timeline- now that I have a reasonable endpoint, the scroll-wheel zoom behavior is normal. I don’t remember it ever behaving correctly before this.