Ardour 9.2 on Windows 10 hangs for 5+ minutes when inserting some VST3 plugins, while 8.12 works normally

#1

Hi all,

I am seeing a reproducible problem with the release build of Ardour 9.2 on Windows 10.

When I select certain VST3 plugins in the Plugin Selector and click “Insert Plugin(s)”, Ardour becomes blocked/unresponsive for more than 5 minutes before the plugin is finally inserted.

This is not an immediate crash, but a very long hang during plugin insertion.

Scope of the problem

So far, I have reproduced this with multiple VST3 plugins, rather than with just one specific plugin.

Reproduction steps

  1. Launch Ardour 9.2 release on Windows 10
  2. Open any session
  3. Open the plugin insert menu
  4. In Plugin Selector, choose one of the affected VST3 plugins
  5. Click “Insert Plugin(s)”
  6. Ardour hangs for 5+ minutes, then the plugin is eventually inserted

What I expected

The plugin should be inserted in a reasonable amount of time, without the whole UI appearing to freeze.

What actually happens

Ardour blocks for several minutes before the insertion completes.

Important comparison

I tested the same behavior on the same Windows 10 machine with Ardour 8.12, and in 8.12 these VST3 plugins can be inserted normally.

So this seems to affect Ardour 9.2, while 8.12 does not show the same issue.

Notes

  • This is with the official release build
  • The problem happens during insertion, not during plugin scanning
  • I would like to know whether this is already known, and whether there is any workaround or fix

Thanks.

1 Like
#2

Can you provide a small list so that others can test and try to reproduce?

  Seablade
#3

I would be curious to know if this happens on Windows 11 as well give Windows 10 support (From Microsoft) is… not ideal.

Seablade

#4

I’m seeing the same issue on Windows 11 as well. I reproduced it on another Windows 11 machine.

#5

Ardour 9.2 on Win11 loads VST3 Airwindows without any problems. I don’t have any other VST3 installations.

#6

juicysfplugin
Ozone 10 VST3
Neutron 3 VST3

#7

On Windows 10, I tried inserting “juicysfplugin.vst3” into a MIDI track a number of different ways, and they all loaded instantly for me. I cannot test the other two plugins because I do not own them.

Ardour 9.2 juicysfplugin
Ardour 9.2 juicysfplugin1366×768 176 KB

#8

I must admit I’ve read several reports of inexplicably long delays (admittedly, mostly affecting Mixbus) either when loading certain sessions, or trying to display certain plugins, or even just trying to launch Mixbus, Generally speaking, Mixbus eventually recovers and then works normally. I’ve managed to reproduce it here when loading certain sessions although I haven’t seen the others. But it only started happening very recently so there does seem to be something weird going on.

#9

Juicy’s plugin for Windows 11 loads the Soundfont in Mixbus 32C

Screenshot 2026-04-14 110430
Screenshot 2026-04-14 1104301911×1078 292 KB

and Ardour 9.2.
Screenshot 2026-04-14 105221
Screenshot 2026-04-14 1052211910×1079 254 KB

without problems.

1 Like
#11

Thanks for testing. I found one more important variable on my side: the issue seems to depend on the Windows Regional format setting.

On the same machine, with the same VST3 plugins:

  • In Ardour 9.2 , insertion works normally when Windows Regional format is set to English (United States) .
  • In Ardour 9.2 , insertion hangs for 5+ minutes when Windows Regional format is set to Chinese (Simplified, China) .
  • In Ardour 8.12 , insertion works normally with both Regional format settings.

By Regional format , I mean the Windows 10 setting at:

Settings → Time & Language → Region → Regional format

This is not the same as the Windows display language.

Microsoft documents the same setting here:
“Change the Windows regional settings to modify the appearance of some data types in Access databases.”

The same setting can also be reached through:
Control Panel → Clock and Region → Change date, time, or number formats

or by pressing Win + R , typing intl.cpl , and pressing Enter.

So at the moment this looks like a 9.2-specific issue that is triggered when the Windows Regional format is set to Chinese (Simplified, China) .

That may be why it is not reproducing on other systems.

2 Likes
#12

Good detail, hopefully some others can jump in and confirm if there is an issue on their end. I would be curious if other languages have the same effect (French, Spanish, etc.) or if all non-english does.

  Seablade
1 Like
#13

Hi, I found another useful clue.

If I start Ardour from cmd with:

set LC_ALL=C
set LANG=C
set LC_MESSAGES=C

then the affected VST3 plugins can be inserted normally, even with Windows Regional format set to Chinese (Simplified, China).

So I checked the source history and noticed that between 8.12 and 9.2, gtk2_ardour/main.cc changed here:

That change removed:

Glib::setenv (“LC_ALL”, “C”, true);
Glib::setenv (“LANG”, “C”, true);

From what I can see, this matches my test results quite well: 8.12 worked normally, while 9.2 can stall for 5+ minutes when inserting some VST3 plugins under Chinese Regional format. If I manually add those env vars back before launching Ardour, the problem disappears on my machine.

So I’m now wondering whether this regression is related to that startup locale change. Would it make sense to restore the 8.12 behavior here, or is there already any plan to fix this in a future release?

#14

Perhaps this is just exposing errors in the plugins. Would be useful to get feedback from the developers of affected plugins.