So recently, I've encountered a bug that will ruin your whole mission. So whenever I tried to rendezvous my craft, the second spaceship will start firing RCS continuously without control. Continuing firing RCS is okay, but what it does next is probably your worst nightmare. Imagine your got 78 science report on your craft, and you finally returned to Kerbin, BUT YOU CANNOT EITHER QUICKSAVE AND RELOAD OR EXIT THE MISSION! The only solution so far is quicksave before the orbital rendezvous or exit the game (You will got a 30-40% chance that you will kill all the Kerbals you were unlucky).
NOTE: It only appears in Apollo-style mission