When starting up the game after the crash it was version 15.16 I know the crash happened on vs 15.15 because that's what the server is running but I didn't notice it updating after the crash, would steam have updated the files while it's running?

vanilla factorio 0.15.15 steam version on mac.

I've been playing on a LAN server for a number of hours with no major issues. (occasional lag spikes but less then autosaves)
The crash occurred directly after putting down an assembler 3, select it and click on the combat tab. I have done that action ...

Was experimenting trying to find more specific reproducability conditions (seems to happen around 9-15 clicks up and down the tech tree) When I got a different error telling me I should post it to the forums (haha, a bit late) I will include the log for this crash as well:

I'm running factorio 0.15.14 (build 30011, mac, steam) without any mods and ran into a crash, when selecting one technology then another from the tree view, doing this a number of times results in a popup saying just "Error vector" and closes.

Screen Shot 2017-05-26 at 10.08.22 AM.png

The last ...