Now I am getting this error message when i try to create a gallery for the Nextgen plugin:
Directory wp-content/gallery/ is not writeable !
Check this link, if you didn't know how to set the permission : http://codex.wordpress.org/Changing_File_Permissions
I checked on my server and for now wp-content/gallery is just an empty folder that i created. How do I make it writable? Or do I have to change permissions on all the files in the admin folder for the nextgen plugin?