Can you submit a ticket (https://esupport.stardock.com/index.php?/Tickets/Submit) with the save game and the custom faction (and any custom ship designs if any) attached so we can take a look?  Thank you.  

You need a descent sized page file for this game.  Even if you have tons of RAM you need a page file.   Set your "virtual memory" to "System Managed Size" or set a custom size of  MIN= 1.5 times installed RAM and MAX= 2.5 times installed RAM.   This will stop memory issues.  The game can fill RAM rather quickly and the PC needs to unload some of it to a page file.   Control Panel > System > Advanced System Settings > Settings button under "virtual memory" > Advanced tab > "change" button for virtual memory > select "Custom" > enter sizes for min/max and click "Set",   OK on everything and reboot.   Also can click "Let Windows Manage...." at the top.

This has been reported in at least two other threads:

[1.5]Games crash when creating or editing Huge ship in designer by LazySiege 

and one started by myself as well (I forget the name - now on page 2 of the forum)

pshaw has been collecting all the tickets so i presume it'll be sorted out in the next patch.

Cheers,

Jon

Update -- we found the issue and will fix it.  Thanks for the information.

The problem was some bad information that only got hit in the ships with the largest physical sizes (not strictly hull sizes).  Not sure when the problem was introduced, but its fixed now in our internal builds.

The fix will be released at the same time as Mercenaries on 2/18.  You do not need the expansion to get the fix.