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IDProjectCategoryView StatusLast Update
0010089ardourbugspublic2026-01-02 18:40
ReporterGhostsonAcid Assigned Tox42  
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionfixed 
PlatformmacOSOSMojaveOS Version10.14.6
Product Version8.12 
Summary0010089: Certain buses do not present themselves as valid Aux Sends even though they should be. [Missing line of code found.]
DescriptionAnother bug, sorry... o___o
--> BUT, this time I managed to track-down an exact line of missing code (for a <Route...) that seems to be causing the issue.

Example Session:
https://www.mediafire.com/file/9uibva7p1gkcsek/Missing+Aux+Sends+-+Example+Session+1.zip/file

First off, I’m pretty sure 100% of these problematic sessions were originally created in Ardour 2.8.16.
So I now conclude some problematic *migration/mutation of the XML file* is to blame.

Second, I still cannot open any of these affected sessions in any version of pre9, as reported here:
https://tracker.ardour.org/view.php?id=10062
(... I'm now beginning to think these issues are somehow related: e.g., XML leftovers/junk causing problems....?)

Third, but I encourage you to FIRST try opening "Missing Aux Sends - Example Session 1.ardour" with the latest *Ardour 9* build.
--> And if ALL 6 buses show-up as available Aux Sends for "Test Track 1", then I guess this problem was somehow resolved, and you can ignore the rest of this post!

...
Anyway, upon my own investigation, the real culprit appears to stem from a *missing* line of code in the .ardour XML for the affected bus (<Route…), namely something like:
<Processor id="2144374" name="Return" active="1" user-latency="0" use-user-latency="0" type="intreturn"/>

I don't know what a line like that does exactly, but what I DO know is that if you add it to the <Route... code for one of these buses that refuses to show-up as an Aux Send option, then it fixes the issue (-and thus shows up).



Thank you for looking! : )
-J

Steps To ReproduceSteps to ‘fix’ this via manual XML manipulation:

1. Open the affected session “Missing Aux Sends - Example Session 1.ardour” using Ardour 8.12 (or 9?).
2. In the mixer-strip box for “Test Track 1”: Right-click —> New Aux Send… —> And observe NONE of the “…OLD” buses are available to connect to.
3. *Quit Ardour.*
4. Open the .ardour XML file with whatever code-editor you use (e.g. VSCodium).
5. Find this area:
<Route version="7003" id="2074886" name="BASS BUS NEW"

6. Notice this line (0000056:0000035 lines below), and copy it:
<Processor id="2074924" name="Return" active="1" user-latency="0" use-user-latency="0" type="intreturn"/>

7. Now find this area:
<Route version="7003" id="37547" name="BASS BUS OLD" …

8. Notice how a version of that <Processor... line doesn’t exist for this “OLD” bus <Route.
9. So paste one there (again, 0000056:0000035 lines below), and change the Processor's id to whatever random number you want.
10. Save the XML.
11. Reopen the snapshot in Ardour 8.12 (or 9?), and notice how you can now add an Aux Send to “BASS BUS OLD”!
Additional Information2 years ago I noticed this issue, and Robin dismissed it by saying:
"Either you already have an aux send to the bus, or making a connection to it would result in a feedback loop. In those cases Ardour does not offer the bus as target.”: https://discourse.ardour.org/t/what-is-the-best-setup-for-parallel-processing-within-ardour/109578/7?u=ghostsonacid

Again, this appears to be incorrect.
Something else is happening here that shouldn't be.
Tagsaux send, buses

Activities

GhostsonAcid

2025-12-31 18:19

reporter  

GhostsonAcid

2025-12-31 18:24

reporter   ~0029642

I made the mistake of using a tilde symbol again... -___-
I just meant "('about 35' lines below)".

-Just FYI.

x42

2026-01-01 20:45

administrator   ~0029644

Nice find!

Do you still have the original 2.x Session?
The file you sent has "Session version="7003" so it already was incorrectly converted. Ideally the missing "Return" will only be added during conversion and not unconditionally at a later stage.

x42

2026-01-01 22:21

administrator   ~0029647

Fixed in 9.0-rc2-31-g8c81e40028

v2.x sessions are now converted properly.
Already converted sessions remain as-is and need session file editing as you mentioned.

GhostsonAcid

2026-01-01 22:27

reporter   ~0029649

Awesome, Robin! : D
Looking forward to this benefit, as I still have like x100 A2.8.16 sessions to 'migrate' to v8.12/9! : D

I was going to get back to you sooner on this, but was instead dealing with investigating (and in some sense slaying) bug 0010062.

Thanks again! : )
-J

GhostsonAcid

2026-01-01 23:23

reporter   ~0029650

And yes, I do have all of the original 2.8.16 sessions.
I'll try migrating a few tomorrow using the latest v9 build.

~Thanks!

GhostsonAcid

2026-01-02 13:18

reporter   ~0029654

> "Already converted sessions remain as-is and need session file editing as you mentioned."

Question: Can I use any random string of numbers for any made-up id?
Is doing so SAFE? O___o

GhostsonAcid

2026-01-02 18:40

reporter   ~0029655

~SUCCESS!!! : D
And you actually likely solved *another* (lesser) issue simultaneously:

When migrating an A2 project to 8.12, not only would the buses not present as valid Aux Sends, but also all buses *would not appear* on the *initial* opening in A8.
This was easily remedied by simply quitting the session, and reopening A8, to which everything would show-up correctly.

Now buses (-as of 9,rc2.38):
1. Appear as valid Aux Sends.
2. Appear immediately!

Good job, Robin! : D
~Thank you so much yet again.

-J

Issue History

Date Modified Username Field Change
2025-12-31 18:19 GhostsonAcid New Issue
2025-12-31 18:19 GhostsonAcid Tag Attached: aux send
2025-12-31 18:19 GhostsonAcid Tag Attached: buses
2025-12-31 18:19 GhostsonAcid File Added: Screen Shot 2025-12-31 at 7.34.24 PM.png
2025-12-31 18:24 GhostsonAcid Note Added: 0029642
2026-01-01 20:45 x42 Note Added: 0029644
2026-01-01 22:21 x42 Assigned To => x42
2026-01-01 22:21 x42 Status new => resolved
2026-01-01 22:21 x42 Resolution open => fixed
2026-01-01 22:21 x42 Note Added: 0029647
2026-01-01 22:27 GhostsonAcid Note Added: 0029649
2026-01-01 23:23 GhostsonAcid Note Added: 0029650
2026-01-02 13:18 GhostsonAcid Note Added: 0029654
2026-01-02 18:40 GhostsonAcid Note Added: 0029655