No state, hack attempt?

Hi Stefano,

Getting the following error:
No state, hack attempt?

From this URL:

http://ec2-54-226-138-235.compute-1.amazonaws.com/wp-content/extensions/newsletter/facebook/login.php?code=AQCadZkyPH-moNEXq92L298znRT2KyFfF_IyNyeVDCNjuZLHir_3WIeBWqGPEYKsHisA3vHeCe8_enRh26y_rz5ZxX2hC0b7DE2X8VlDK3Az95RdeOyelC7X6Q2vWakwavDC-KgL7Z52F5i-lBTN1ac0v4xz8LUd-mFj5Ibr168Ot6j9cuTJ6J_u4vo0iSmu7gk9_kMG_zsdoOzRsfOumLLN55BW5Gr60Qk3kmylCBOvMuBC2JdbrlMuO0tZlR47RX_FbugKQHmFNZ2c4cHaLgfk_bY_UyEHOHsPZDLYgRAq8h-tn2ss7libWBbdaA-LH-4&state=f3acccb034c05617ed214f4c4e8c5218#_=_

Thanks for replying to my last question. I gave up on WordPress on Heroku and now I’m on AWS (Ubuntu, Nginx, Varnish). Everything was working on a different instance just fine but now this error happens.