The sync endpoint has been removed

Hi to all, while I am using plaxo to work on my contacts, I encountered an error, the error is about the sync endpoint has been removed from sync dashboard, posting herewith is the error message screen.
This sync endpoint has been removed
from your Plaxo sync dashboard
You must set up Plaxo to re-establish a sync link.
As I am wondering on the error, it is an error about some setup, I don't remember doing some changes on my setup, I've been using plaxo for days ago without any problem, and all of a sudden this problem came about, I checked on the internet for some similar problem I experienced, but I found nothing, I hope my post here will give me an idea in solving the problem, please share your ideas, thanks a lot.
