For me it is definitely not AI or traffic as I don''t have any of it activated.
Until yesterday I was almost sure that it was related to Real Weather Connector - starting roughly 2 months ago I started from (almost) plain X-Plane to gradually re-activate (i.e. move back to the plugins folder) my handful of plugins in order to track this thing down. The last one remaining was RWC and I didn't have a single CTD during this whole period.
Alas, on my last flight yesterday (basically when I had just decided: maybe the issue was somehow fixed by XP 11.40, let's re-animate RWC) I had the ominous CTD again. So now I know, it is NOT RWC!
What I did notice I couple of times in the log files, that just before the CTD there would be entries from SkyMaxx Pro updating weather...
Anyhow, I guess I will just live with it as I do get the CTD only very occasionally (1 out of 10-20 or so flights), most of the flights work out as expected.