Common Error (message Failed)

Hi

I Using WordPress and I Using Facebook comment plug in but when someone try to Submit Comment I Got That Error Say Failed. What Is The Cause Of that Error Please see This screenshot https://box.everhelper.me/attachment/634148/4b7ae579-d5c5-41be-8d31-32ed9d52b1a2/674713-WLBmWns9SJIdNNfv/screen.png

Thanks Please Help Me My Email is davidmchomvu1@gmail.com
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