every page is blank

Hi people, I’ve got a trouble yesterday. I updated nextGen plugin and now I’m not able to edit anything.. There was a problem before I got it updated, too. I wasn’t able to add galleries, so I upadted nextGen. Then it worked pretty well, but sometimes I’ve got an empty site like now, but the page-content appeared after reloading..I deactivated nextGen and then no problem occured. I saw that there was a new update. So I updated it again, I activated it, and now I can do nothing ’cause all I get is an empty page. My web is working well for visitors, but I’m logged in like an admin, and if I want to enter dashboard, or edit a page, I’ll get a blank site. Please please help me quickly, I do not know what to do