same here.
To verify that it isn’t a issue with my mainpage, I have install a DEV Page for myself with only NextGEN 2 and it’s not possible to create a gallery or upload any Pictures (with the uploader)
When I create the Gallery in the “Manage Gallery” menue, the folder on the FTP site is generated, but when I’ll sth. add to the folder, nothing happened.
(WordPress 3.6 / Nextgen 2.0)
