edstirling

I'm having a problem with kerbal attachment system. So I've got Thomdon Kerman on EVA to move one of those removable docking ports and he's got it on his back and i right click the thing, click attach and it says "attachment pointer active" BUT it doesn't show me the little green cross on the fuel tank i'm trying to put it on. pretty certain it's within the little kerbal's reach, but it should be a red cross if not and there's just no cross/pointer thing at all. tried just clicking the tank anyway but nothin' doin'. Is this a .21 issue?