Crash: Modifying formation to unavailable ship

I’ve played with a formation with for ships connected to a cruiser.
I upgrade my cruiser design and gave it a new name and deleted the old design.
When loading an old deployment GSB happily removed the old cruiser from the formation.
So far so good, but when trying to change the formation order GSB crashes every time.
(Solution for me was to change formation to keep moving and the re-setting the formation)