Ardour suddenly turns off

[atux]

Hi all,

while working on a multi-track MIDI project, Ardour suddenly shuts down…
I reopen the project, it asks if I want to recover it, I say yes, it opens but after a few seconds, without doing almost anything, it shuts down again.
I believe it happened after inserting some linear tempo changes.
(I was also working on fader automation).

This is the message in the terminal:

~$ ardour-7.4.0: ../libs/temporal/tempo.cc:505: Temporal::superclock_t Temporal::TempoPoint::superclock_at(const Temporal::Beats&) const: Assertion qn >= _quarters’ failed.
`

Now what interests me the most is how can I recover the project, even without the tempo changes, as long as it gets back to working.
[Ardour 7.4 built from source on Ubuntu 22.04]

Thank you,
a.

[atux]

I managed to recover the project: as soon as I opened it, I had time to “save as”, without touching anything else (otherwise it would turn off), so I saved it with another name, canceled the tempo changes (ramp) and the project was once again stable.
However, the problem of inserting linear tempo changes remains. I could try on a copy and see if the problem repeats. If it happens again I’ll update this post reporting the error messages.
a.

[ccaudle (Chris)]

Have you checked with 7.5? Tempo maps were one of the improvement areas for that release.

[atux]

I built version 7.5 successfully some time ago, but it gave me other problems that with projects already in an advanced state, I preferred to go back to 7.4, more stable on my system, to be able to finish them.
For example, as I wrote in another previous post, in version 7.5 as soon as I execute the “Deinterlace Into Layers” command in a MIDI region, Ardour suddenly shuts down.
When I start new projects, I will try the 7.5 version again and present the problems that arise.
a.