I just upgraded INDI and KStars to todays git versions.

Starting up EKOS, it won't connect to the ZWO cameras (neither my 1600 nor the 290mini). Same issue with previous KStars (that had worked before).
Downgrade INDI to previous state (libindi-1.8.5-127_g3ecc2737) and cameras are there again...

clarification:
there again = I can connect and use. They were discovered before, too, just 'connect' fails

Can't replicate this here, both ZWO cameras connect fine (178 & 120)

Mine work, too. No problem with connecting after installing from the latest git. The crashes are gone and all the peripherals are recognized again for me.

Well, I never had crashes anyhow (seems those having them were using Pis?). But as described, its very repeatable linked to the INDI version.
I'll try to run with INDI logging/debugging active tomorrow, maybe that gives a hint.

I am having the same problem. After updating the indi driver keep crashing when I try to commect to my zwo120mc.

Does it really crash, or also just sit there, not connecting?

So I just went through it again. All tests done with the same kstars version compiled from git, kstars-3.5.0-1363_ga2149a13a (Aug 27).
Attached two logfiles, log_10-16-58.txt and log_10-21-15.txt (as TAR archive). First one is with indi version 1.8.5-127_g3ecc2737 as of August 6. It is set for autoconnect, and both cameras do connect. I then just disconnected, and quit.
Second run is identical, but with INDI version 1.8.6-5_ge342163a (Aug 28). The cameras don't connect. In the camera tab, 'Connect' is highlighted, the button is yellow. No details visible. Pressing the 'Disconnect' button in the Settings tab of EKOS disconnects all other devices, the two ZWO cameras stay in the state 'yellow' and 'Connect' highlighted.
I could however not see any hint in the logs that would suggest what the problem is. Maybe someone else can.
Else I'd appreciate some hint what to try to narrow down the problem...

I had tried downgrading only indi_asi and libasi to the working version, but that still failed, not connecting to the camera. So likely some interface has changed?.

my ASI120MC having issues of kipping frames after update to the latest version.

One approach is try to see if it is an SDK issue. Check the libasi history here:

github.com/indilib/indi-3rdparty/commits/master/libasi

You see the hash number for each commit. You can use GIT to checkout a specific commit and then compile this. For example, suppose you are in ~/Projects/indi-3rdparty directory, you can do this:

This would checkout version 1.5.0430.

Then you need build and install this sdk, and then recompile indi-asi, and then test.

You can also go to older SDK from Dec of last year (d6bf47d90b6d95d88720fcbd74671c1cc7a8446e)

If the SDK rollback still has issues, you can rollback indi-asi as well.

Thanks for the guidelines. First time I tried that, so it took a bit...
But yes, I can confirm that if I build the current INDI git against the previous ASI SDK version 1.5.0430, both cameras connect properly again (as do the other ZWO devices, EFW and EAF).

This BTW is the x64 version, in case it's important.

Seeing that ZWO had released new camera drivers/SDK, I compiled todays git of INDI and KStars using that new SDK (1.15.0915).
No problems anymore detecting and connecting to my cameras (1600MM, 290MMmini, 183MC), imaging works, too