I'm just using the standard built-in Windows Security software, I've never had any issues with it before but I will try disabling it next time. As it happens I had another crash this morning, before I read your post, when I was processing the subs I captured last night. Slightly different manifestation of the same issue, here's what happened:
Open PI, apply outstanding update to image integration (but didn't restart).
Open Blink.
Open in turn 8 sets of FITS files, approx 150 files in total, and in each set inspect each image and close it, as described in the previous post, and then open the next set.
After closing the last image from the 8th set, click the open files button and browse to the folder where the 9th set of files are located. I want to create a sub-folder in that location so before selecting any of the files in the file explorer window, I right click and type W,F but PixInsight has already crashed. It happened very quickly, I didn't notice if the Window's file explorer context menu was displayed in response to the right click. The Process Console was not open but in any case the crash was instant so I don't know if PI wrote any error to the console. Windows recorded 2 crash events in the app event log (see attached).
I restarted PI and Blink, browsed to that file location again and this time there was no problem creating the sub-folder and processing the files.
I've never had any issues like this prior to 1.8.8 and my PC hasn't changed for 3 years. As I said, next time I'll try disabling Windows Security before blinking through my subs but I really doubt that could be a factor.