We pushed a built recently that deals with crash recovery (not complete yet but should help). Built on 2023.12.11

Thanks Jasem, like I said, Kstars recovers fine, it doesn't close, but the driver is gone. Does this build deal with anything that can help with the camera disappearing?

Just updated to the 2023-12-11 build.
Same behavior.
Here's a log copied at the moment the first capture after meridian flip froze.
I had to click stop for it to continue. This scenario is usually followed by a crash in about 10 minutes, you can see the crash in the previous log I posted, unfortunately I'm getting clouded and I have to shutdown.

@jasem the reason why recovery is not possible in this case is because even though KStars doesn't crash fully, after indi-asi exits with -1 per log, the camera disappears from the Server and won't come back until the server is manually stopped and a new one restarted.

I sometimes get similar issues with QHY268M, where Ekos gets stuck downloading a captured frame. It is not related to meridian flip and I do not have any logs to support my case at the moment, but it just fails to download a frame, restarts capturing at some point, then hangs again until I notice it. Disconnecting the camera driver from the INDI control panel and reconnecting it back always helps, so these days before I set off with a long sequence, I always check one sub if it's OK and only then start the scheduler. Does not happen often at all.

After 3-4 hours of capture without problem, I have also problem with "Downloading..." stuck after a meridian flip, stopping it and I can continue to capture.

So problem comfirmed also with Touptek driver updated (IMX585 cooled) and Star Adventurer GTi.

Hi
Also with omegon veTEC. I think this is the same issue:
www.indilib.org/forum/ccds-dslrs/14136-o...ra-disconnected.html

Log attached to that post.

Thanks

We can use this workaround, example M78 capture a few minutes before FLIP, and restart a few minutes after, so align is not triggered, night goes ok! 300 capture without a problem.

So I can confirm that there is a problem, with ALIGN & CAPTURE stuck in downloading after a Meridian Flip.

This makes no sense to me, why would it just get stuck after meridian flip? In the INDI control panel, is the camera stuck? aborting and restart from INDI control panel works?

Jasem, thanks for reading, if you look at my logs at the beginning you can see that apparently Ekos does not acknowledge the driver successfully completing the exposure. The driver does not report anything abnormal and completes successfully, but Ekos is stuck on Downloading. An abort from Capture itself (stop button) will unfreeze it. But after a few exposure, the camera driver crashes and exit with -1, without anything in the logs justifying it.
The meridian flip part is not logical, you're right, but I did some dry runs for you on a bad weather night, and I could repro this 5 times in a row, always after a flip. Empirical, but consistent! Logs always look like the ones I posted above.

Exactly the same for me "Downloading..." stuck, I press "stop capture" and can continue (I didn't have the patience to wait for the camera driver to crash yet).

The first time, I only noticed it in the morning, everything else seemed to still work.

But I can add some hint, during that night I have 2 flip (on 2 different target), first one aborted a capture and the capture resume correctly, after the second flip, "Downloading..." stuck, seem like the capture BEFORE flip leave some problem, that can't resume after the flip.

Hi
Thanks @FRANSESCO. Your workaround looks promising.
In my case, after the flip, the camera disconnects. The driver needs to be restarted to carry on the schedule:

[2023-12-20T01:41:49.095 CET INFO ][ org.kde.kstars.ekos.mount] - Meridian flip: slewing to RA= "06h 20m 42s" DEC= " 22° 33' 19\"" Hour Angle "00h 00m 50s"
[2023-12-20T01:41:49.095 CET DEBG ][ org.kde.kstars.ekos.mount] - Setting meridian flip status to "MOUNT_FLIP_RUNNING"
[2023-12-20T01:41:49.095 CET INFO ][ org.kde.kstars.ekos.mount] - "Meridian flip running..."
[2023-12-20T01:41:49.095 CET DEBG ][ org.kde.kstars.ekos.capture] - updateMFMountState: "MOUNT_FLIP_RUNNING"
[2023-12-20T01:41:49.095 CET DEBG ][ org.kde.kstars.ekos.capture] - updateMeridianFlipStage: "MF_INITIATED"
[2023-12-20T01:41:49.095 CET DEBG ][ org.kde.kstars.ekos.capture] - Capture State changes from "Calibrating" to "Meridian Flip"
[2023-12-20T01:41:49.101 CET INFO ][ org.kde.kstars.ekos.align] - Target coordinates updated to JNow RA: "06h 20m 42s" DE: " 22° 33' 19\""
[2023-12-20T01:41:49.198 CET DEBG ][ org.kde.kstars.ekos.scheduler] - Capture State "Meridian Flip"
[2023-12-20T01:41:49.199 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Starting Goto RA=6.34487 DE=22.5552 (current RA=6.33959 DE=22.5663) "
[2023-12-20T01:41:49.200 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] GOTO ALign Nearest: delta RA = -0.005430, delta DEC = 0.008842 "
[2023-12-20T01:41:49.201 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Aligned Eqmod Goto RA=6.33944 DE=22.564 (target RA=6.34487 DE=22.5552) "
[2023-12-20T01:41:49.201 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Setting Eqmod Goto RA=6.33944 DE=22.564 (target RA=6.34487 DE=22.5552) "
[2023-12-20T01:41:49.202 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Slewing mount: RA increment = -5567912, DE increment = 4171970 "
[2023-12-20T01:41:49.203 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Slewing to RA: 6:20:42 - DEC: 22:33:19 "
[2023-12-20T01:41:49.203 CET DEBG ][ org.kde.kstars.ekos.capture] - updateMeridianFlipStage: "MF_FLIPPING"
[2023-12-20T01:41:49.216 CET INFO ][ org.kde.kstars.ekos.guide] - "PHD2: Guiding Stopped."
[2023-12-20T01:41:49.216 CET DEBG ][ org.kde.kstars.ekos.capture] - Guiding state changed from "Guiding" to "Aborted"
[2023-12-20T01:41:49.219 CET INFO ][ org.kde.kstars.ekos.guide] - "Autoguiding aborted."
[2023-12-20T01:41:49.219 CET DEBG ][ org.kde.kstars.ekos.scheduler] - Guide State "Aborted"
[2023-12-20T01:41:49.287 CET INFO ][ org.kde.kstars.ekos.guide] - "PHD2: Lock Position Lost."
[2023-12-20T01:41:49.548 CET DEBG ][ org.kde.kstars.ekos.mount] - Mount status changed from "Tracking" to "Slewing"
[2023-12-20T01:41:51.055 CET INFO ][ org.kde.kstars.ekos.guide] - "PHD2: Guiding Stopped."
[2023-12-20T01:41:51.056 CET DEBG ][ org.kde.kstars.ekos.scheduler] - Guide State "Aborted"
[2023-12-20T01:41:53.008 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Align: current point is 2 "
[2023-12-20T01:41:57.034 CET INFO ][ org.kde.kstars.indi] - EQMod Mount : "[INFO] Align: current point is 0 "
[2023-12-20T01:42:11.234 CET INFO ][ org.kde.kstars.indi] - Astroshop veTEC571C(USB2.0) : "[ERROR] Camera disconnected "
[2023-12-20T01:42:11.485 CET INFO ][ org.kde.kstars.indi] - Astroshop veTEC571C(USB2.0) : "[ERROR] get Temperature error. Generic failure "

After which there is no further capture.
Thanks for taking a look.
Steve