I'm new to KSP and there are two bugs that I find very bad for gameplay and from looking for solutions it seems these two have been known for years (but not fixed??).
1) Docking ports sometimes "stick" (as in sometimes you click "undock" but the two ships remain locked in an eternal, unbreakable embrace).
2) Cloning or what I like to call "ghost" Kerbals. When you EVA and try to re-enter the vessel but a clone or ghost Kerbal is left clinging to the outside of the ship (preventing time acceleration and causing other problems until the system crashes or you get frustrated and revert to an earlier save).
