Demo Content file not installing or Downloading content

I just bought this theme and i tried importing the demo content through the content.xml file but after uplaoding and i'm asked to assign the contents to a user which i did and ticked/checked the download all files box. the screen will just go blank the load the wordpress menus and write importing wordpress... and thats all nothing happens no content is imported or downloaded to the site. help me install the demo content please. thanks