I had a fleet of 11 freighters, with one normal cargo bay (25k tons) each. I tried to load one Spaceport and eight Financial Centres into the fleet. The tick after making that order, I'm getting a mountain of "Object reference not set to an instance of an object" errors. It's cycling through functions #222, 224, 2339, and 2608. I went through this cycle manually about 40 or so times without it stopping, then just held down Enter on the error message for another 5-10 seconds until it finally finished popping up.
Edit: Tried it again, this did not recur. And I see the same bug report from someone else that was seemingly unrelated. Perhaps I have a false cause here.