I had this with a site and backing down NextGen to 1.9.13 fixed the problem.
Here are some instructions: http://www.nextgen-gallery.com/how-to-rollback-a-version/
You can select an older version of the gallery here: http://ww.wp.xz.cn/plugins/nextgen-gallery/download/
Can you move/remove your plugins and retry? Whenever I”ve gotten a blanked dashboard it was a plugin issue. Could it be a plugin related to some PHP library unavailable on your hosting? Just a shot in the dark with that thought since it had worked in another environment.
