Here we have lot of possibilities but solutions as following.
Solution1: Remove total robots.txt and add following robots.txt
User-agent: * Allow: Sitemap: http://www.example.com/sitemap.xml
Solution2: Check weather urls contain ‘/’ at end , then your web master tool will treat your urls as directories.
Incorrect Url: http://www.example.com/home/
Correct Url: www.example.com/home