Facebook problem on my E7 after last Facebook update today, how can I fix it?

Hi,

I have updated my facebook today on my Samsung E7 and when I tried to open the application it gives me the below message and reject to open

sorry unable to login to facebook. please check your network connection or try again later (httpNetworkException:proxy HTTP status 400)

I have tried everything but nothing work same message.

Try clearing the cache/data on the app from Settings > Application manager, then force stop.