would like to share with you. I use my recent bought Leonardo, uploaded software on it, afterward, I found I can't upload anymore again. that's weird, due to the system still recognized by IDE,
My solution is using the older IDE 1.6.0 version, program the blink again, I found this works and it can be wake up the board again. The new IDE programming working good again. I nearly throw away all malfunction Leonardo. haha.
** time being, I am trying to use Leonardo as a Keyboard simulator, I thought this might be related to this issue from the beginning, but finally, I found this is not!
Any people who have the same please report, Maybe my case not unique. this can help the Arduino team follow up.