I finally ground up the rep to fit my salvaged Odysseus Vanguard with the Main Batteries, and when I did, it broke my ability to modify the ship any further
. I built one from scratch to test it, first building w/o the Main Batteries, then the #1, followed by the #2, and encountered the bug once I installed the #2 Main Battery (which has an upside down hit box for some reason, relative to #1..).The bug manifests itself by allowing you to change one item, then locking out any further clicking. Not even the remove position button works. If you attempt to click the 'Add to Cart' button, the screen will go black and the ship clears itself. You can re-select the ship, but can still make no further modifications to it. It won't add the changes to the cart, and you can't finalize them.
I'm not sure (I didn't think to test it before I signed off for the night), but I suspect it's something to do with the #2 battery, as the #1 didn't seem to cause any issues. Worth testing, but at least you should be able to replicate it using the steps I listed above (Or, my game is broken, ha).