can not add a new value in a custom list

I running: - a windows server 2012 - using sharepoint 2013. - visual studio 2013

I created a custom list in visual studio and when i'm trying to add a new value inside I got "unexpected response from server: Error 400 bad request".

I found "The web browser may be too recent, or the HTTP server may be too old" which is the corresponding description for this error. Of course it doesn't help me.

Why am I having this message. Could someone help me?