I haven't really played Arma 3 for a couple of months, But I just played on a custom mission for a good 20 minutes and I haven't crashed.

I don't think that's it for me, none of my computer hardware is overclocked.
But good to see atleast some people may be able to fix it until BIS finds out what's causing it

I forgot to add, that I am running Arma 3 Alpha (not Lite), and I do not have Development Branch enabled in Steam properties