Hi @onefang Thanks for the song files.
I got Surge 1.7.1 LV2 installed.
I am seeing crashes with your file but it is not clear if they are the same crashes that you are getting.
As soon as I got Surge installed it started crashing. Previously it was not, even with Yoshimi installed.
So... There are a few things going on here.
1) Your original song file is missing some tracks.
Or, more precisely, there are mixer strips and routing connections in the song file that reference non-existent tracks.
I counted 63 tracks total in the song:
1 AudioOutput
37 MidiTrack
1 AudioInput
9 WaveTrack
9 SynthI (6 Surge-LV2)
1 AudioGroup
5 newdrumtrack
0 aux track
Thus, a valid track index which other items in the song file can reference is 0-62.
And yet, there are mixer strips and routing connections in the song file that reference track indexes 63-67, which are invalid.
The cure is not a simple matter of removing the references to track indexes 63-67, because the missing tracks
seem to be scattered among all the other tracks. I tried that.
For example a routing connection is expecting a midi track at say, index 40, but the track currently at index 40 is not a midi track.
Thus it seems some tracks are missing, scattered throughout the list of tracks, not just at the very end of the list.
This is puzzling. Not sure how tracks could go missing, while invalid mixer strips and routing connections were kept in the file.
2) I tried removing the excess track references, and all customData tags (which can cause problems if a newer version
of a plugin is being used - the existing customData might be alien to the new version).
No luck, still crashing.
3) I tried replacing all Surge LV2 instances in the file with the latest Surge XT LV2.
Well, no luck yet, it crashes my desktop, likely due to runaway memory use, I probably have done something wrong
and I think I may have to remove all the controller tags to make it work. Jury is still out on this one...
4) I am now recalling that we have been down this road before, here on LM, with @Impostor 's bugs.
It seems too many multiple instances of Surge might be causing a problem.
For the record, the crashes are occurring in the audio process call when we ask Surge to process audio.
This is not good, and indicates the same problem @Impostor was having, if I recall correctly.
The crashes are not occurring in our code, they're in Surge.
Seems multiple Surge (and others?) are fussy with MusE, possibly something about the track order makes it happen.
I note that I can make a project with multiple Surge XT and it runs fine so far, but I suspect that if I add more,
or arrange the tracks a certain way, it will crash. That seemed to be the case with @Impostor 's bugs as well.
I will try to make that happen here with XT...
Still investigating this mystery.
Sorry about the trouble.
I hope you were able to get some work done this weekend.
T.