I have tested this bug out and found where the issue lies:
If you have a drone docked to a mother ship on a rail, then change out the rail it is docked on for a shoot-out rail the invalid position error occurs.
A workaround for this is to only swap out the direction of the rail your ship is docked to and have it lead to a shoot-out rail.
I was able to re-produce this bug with the supplied blue-print and the workaround consistently solves the issue.