sync error uploading to Crius board with MultiWii 1.9

I'm sure this has been covered but I'm too old to read hundreds of pages of posts. Here's my error:

avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

I've read about this from one other poster but I'm not smart enough to understand his fix. So dumb it down for me......