Can't make a move?????

I have attempted for the past three days to make a move in one of my games (#6440510). I can move the piece, but when I hit "submit" the piece returns to its starting place and the squares from where it was moved to where it SHOULD have ended both turn PINK. I started trying to make the moves from my home PC and thought it might be that there was a problem because maybe I had left myself loggedin at work...but when I returned to work, I was not loggedin. So I logged in and attempted to make the move....still would not let me.
Now it gets stranger..... as I have several other games underway. I was able to make moves in all the other games.
Now the reason this was such a problem was because my time was about to expire (long story...my illness...wife surgery....) anyway... the time has now expired in this game and it might all be a mute issue anyway, but I would like to know what is going on so that I don't face this in the future....
Any help would be apprciated!
Thanks,
EdT

Please disregard.... I am a dumb*ss! My king was in check!.... Must be the meds I am on to have missed that! Geesh.....
EdT

For future reference, any time you try and submit a move and the squares turn red or pink, that means whatever you are trying to do in not a legal move at that particular time.