Yeah, I already checked that everything was up to date.
Oh, I would have though it was caused by either an up-to-date Scy with an outdated TwigLib or vice-versa. Well, I'll take a look tonight.
Here is some more detail on the bug:
I first experienced it in a battle with some pirates who had a number of Scy ships, this was a one off occurrence of the bug because after I reloaded from my save I did not see that fleet again. The second and third time it happened was with the same Scy fleet. I had saved and there was a Scy strike fleet that was hostile to me passing by, I engaged it and when I fired on one of the ships with a Scalaron cannon mounted on my Nevermore I instantly got the crash. I reloaded and tried engaging the fleet again and the exact same thing happened, crash on a Scalaron shot hitting a Scy ship. Later on I encountered a Scy Hit fleet and had no choice but to engage, at this point I no longer had the Scalaron cannon equipped and I don't think any of the other ships in my fleet had one either, this time I did not get any crashes. So yeah, I think it might be something about the Scalaron and TwigLib not interacting properly.
Anyway, I hope the extra detail helps a bit.