Here is the sw-cp-server error log:
2014/06/26 06:38:20 [error] 712#0: *180 open() "/opt/psa/admin/htdocs/robots.txt" failed (2: No such file or directory), client: xxx.245.xx.133, server: , request: "GET /robots.txt HTTP/1.1", host: "5.xxnwxx.anxxexxe.net:8880"
2014/06/26 08:27:17 [notice]...