Error when to run rsync

Dear all,

I am beginner in ubuntu coding.But i need to install a software using ubuntu. I try apply code provide by the software developer like below:

sudo rsync -avz --delete .

after run this code, should be ask password but appear error like this:

rsync error: error in rsync protocol data stream (code 12) at io.c(764) [Receiver=3.0.9]

Can anyone help me what the problem....