4 out of 5 times, after a meridian flip, I see the first capture stuck in "Downloading" state.
A look at the logs reveals that zwo driver reports the blob transfer is complete, but Capture aborts the exposure.
When this happens, I have to click the stop button in Capture for the Scheduler to force a restart of the capture, which will be always successful.
The problem is that, after that, it's just a matter of time before the driver will crash.

The crashes goes like this:

-Driver reports capture complete
-Capture says it's not timeouts, then restarts the capture
-Driver again reports complete
-Capture restarts the driver
-INDI Server detaches the driver.

The recent update to kstars to survive camera driver crashes allows Kstars to stay open, but the camera will still disappear and require a Indi Server restart, with consequent thermal shock to the camera because the cooler is turned off in the process.

I am experiencing this very frequently, and with no evident pattern.
Disclaimer: I already tried changing usb cables, that is not the issue.
The camera is a ASI1600MM-Pro running direct to computer, no hubs.
I also have a 224MC plugged (also direct to computer) working as guide camera.
This has been going on since 3.6.6, I waited to see if we'd get better, but unfortunately it's still happening on 3.6.8.

Attached is a verbose log including the Capture module, INDI and CCD driver.

Crash happens at the 20:38 hours, several exposures after the failed exposure just after the meridian flip.

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.