When 2 transports attack 2 planets in single turn, first dialog box pops up & ask if your sure, click yes. Before win/fail dialog pops up second attack dialog pops up to ask if your sure, click yes. Dialog pops up for win/fail for second planet, first planet now becomes unconquerable. No transport can attack. Made sure no ships defending by attacking with attack vessel - no change. Cannot convert planet with culture. Was finally able to convert planet with Benevolence tree except for 1 planet. No victory possible.
