Mm, might be an issue with the calibration data somewhere. Could you try without darks to see if that solves it?

I had this happen before too. What I do now is first make all the calibration masters (one at a time), then I restart APP, load all the lights for all sessions and attach the masters. This usually solves this for me.

Hope this helps!

Yes, you were right.

It's a multisession stack and I wrongly loaded all my lights into their respective sessions, instead all-in-one, as per the software's recommendation.

Thanks

Same here

First attempt:

1.083.2 beta. About 400 light frames (three sessions) with corresponding calibration shots (flats, Dark flats, and two sets of darks - the first session had different time and gain).

On Mac with Catalina. Crash with java:266 error. Sigh.

Second attempt: 

Let's try it now on a windows computer (win 10) with a fresh installation of APP. 1.082 just downloaded. This time I use the calibration masters, as APP had created them in the previous attempt. Crash with java:266 error. Ainsss.

Third attempt:

Back to the Mac computer. This time I choose three already calibrated images from another object (Ha+OIII+CMOS). I upload them as lights and press the integrate button. Crash with java:266 error. Argg
I attach screenshots. I don't know what to do anymore... This has never happened to me before... Any guidance on what I'm doing wrong

So did you try a stack without calibration files, as mentioned above? Just to see if APP hits an error due to a problem in the calibration data?