NextGen 2.0.17 – gallery doesn't work

Hi. I update my nextgen to wersion 2.0.17. My WordPress wersion is 3.6

I go to the gallery site and only what I see is empty white site …. (no wordpress site – but only white empty site).
When I go to settings of this site – I can see the content of site.
Next thing is when I open settings of nextgen gallery plugin I see this:

“The session has expired

Please log in again. The login window will open in a new window. After logging in you can close it and return to this page.”

so I log in again – open the nextgen gallery settings and I see again this text….
Gallery doesn’t work – settings doesn’t work….

Site of gallery:

http://semir444.vot.pl/wcszasybulgaria/galeria/