I have mono 2.11 set up with my nginx 1.0.15 webserver running on centos 6.2. I built it from source and xps2, xps4 and fastcgi-mono-server2 work as expected. The problem is when I try and run fastcgi-mono-server4. When I run: fastcgi-mono-server4 /applications=site:/:/srv/www/html/ /socket=tcp:127.0.0.1:9000 /loglevels=Debug /printlog=true Here is what I get from fastcgi-mono-server2: [2012-06-06 23:51:07Z] Debug Record received. (Type: BeginRequest, ID: 1, Length: 8) [2012-06-06 23:51:07Z] Debug Record received. (Type: Params, ID: 1, Length: 801) [2012-06-06 23:51:07Z] Debug Record received. (Type: Params, ID: 1, Length: 0) [2012-06-06 23:51:07Z] Debug Read parameter. (QUERY_STRING = ) [2012-06-06 23:51:07Z] Debug Read parameter. (REQUEST_METHOD = GET) [2012-06-06 23:51:07Z] Debug Read parameter. (CONTENT_TYPE = ) [2012-06-06 23:51:07Z] Debug Read parameter. (CONTENT_LENGTH = ) [2012-06-06 23:51:07Z] Debug Read parameter. (SCRIPT_NAME = /) [2012-06-06 23:51:07Z] Debug Read parameter. (REQUEST_URI = /) [2012-06-06 23:51:07Z] Debug Read parameter. (DOCUMENT_URI = /) [2012-06-06 23:51:07Z] Debug Read parameter. (DOCUMENT_ROOT = /srv/www/html) [2012-06-06 23:51:07Z] Debug Read parameter. (SERVER_PROTOCOL = HTTP/1.1) [2012-06-06 23:51:07Z] Debug Read parameter. (GATEWAY_INTERFACE = CGI/1.1) [2012-06-06 23:51:07Z] Debug Read parameter. (SERVER_SOFTWARE = nginx/1.0.15) [2012-06-06 23:51:07Z] Debug Read parameter. (REMOTE_ADDR = 192.168.128.121) [2012-06-06 23:51:07Z] Debug Read parameter. (REMOTE_PORT = 62326) [2012-06-06 23:51:07Z] Debug Read parameter. (SERVER_ADDR = 192.168.128.125) [2012-06-06 23:51:07Z] Debug Read parameter. (SERVER_PORT = 80) [2012-06-06 23:51:07Z] Debug Read parameter. (SERVER_NAME = site) [2012-06-06 23:51:07Z] Debug Read parameter. (REDIRECT_STATUS = 200) [2012-06-06 23:51:07Z] Debug Read parameter. (PATH_INFO = ) [2012-06-06 23:51:07Z] Debug Read parameter. (SCRIPT_FILENAME = /srv/www/html/) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_HOST = site) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_USER_AGENT = Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_ACCEPT = text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_ACCEPT_LANGUAGE = en-us,en;q=0.5) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_ACCEPT_ENCODING = gzip, deflate) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_CONNECTION = keep-alive) [2012-06-06 23:51:07Z] Debug Read parameter. (HTTP_COOKIE = ASP.NET_SessionId=0176BE8FC161E702439D3C91) [2012-06-06 23:51:07Z] Debug Record received. (Type: StandardInput, ID: 1, Length: 0) [2012-06-06 23:51:08Z] Debug Record sent. (Type: StandardOutput, ID: 1, Length: 196) [2012-06-06 23:51:08Z] Debug Record sent. (Type: StandardOutput, ID: 1, Length: 128) [2012-06-06 23:51:08Z] Debug Record sent. (Type: StandardOutput, ID: 1, Length: 0) [2012-06-06 23:51:08Z] Debug Record sent. (Type: EndRequest, ID: 1, Length: 8) And this is what I get from fastcgi-mono-server4: [2012-06-06 23:50:52Z] Debug Record received. (Type: BeginRequest, ID: 1, Length: 8) [2012-06-06 23:50:52Z] Debug Record received. (Type: Params, ID: 1, Length: 801) [2012-06-06 23:50:52Z] Debug Record received. (Type: Params, ID: 1, Length: 0) [2012-06-06 23:50:52Z] Debug Read parameter. (QUERY_STRING = ) [2012-06-06 23:50:52Z] Debug Read parameter. (REQUEST_METHOD = GET) [2012-06-06 23:50:52Z] Debug Read parameter. (CONTENT_TYPE = ) [2012-06-06 23:50:52Z] Debug Read parameter. (CONTENT_LENGTH = ) [2012-06-06 23:50:52Z] Debug Read parameter. (SCRIPT_NAME = /) [2012-06-06 23:50:52Z] Debug Read parameter. (REQUEST_URI = /) [2012-06-06 23:50:52Z] Debug Read parameter. (DOCUMENT_URI = /) [2012-06-06 23:50:52Z] Debug Read parameter. (DOCUMENT_ROOT = /srv/www/html) [2012-06-06 23:50:52Z] Debug Read parameter. (SERVER_PROTOCOL = HTTP/1.1) [2012-06-06 23:50:52Z] Debug Read parameter. (GATEWAY_INTERFACE = CGI/1.1) [2012-06-06 23:50:52Z] Debug Read parameter. (SERVER_SOFTWARE = nginx/1.0.15) [2012-06-06 23:50:52Z] Debug Read parameter. (REMOTE_ADDR = 192.168.128.121) [2012-06-06 23:50:52Z] Debug Read parameter. (REMOTE_PORT = 62326) [2012-06-06 23:50:52Z] Debug Read parameter. (SERVER_ADDR = 192.168.128.125) [2012-06-06 23:50:52Z] Debug Read parameter. (SERVER_PORT = 80) [2012-06-06 23:50:52Z] Debug Read parameter. (SERVER_NAME = site) [2012-06-06 23:50:52Z] Debug Read parameter. (REDIRECT_STATUS = 200) [2012-06-06 23:50:52Z] Debug Read parameter. (PATH_INFO = ) [2012-06-06 23:50:52Z] Debug Read parameter. (SCRIPT_FILENAME = /srv/www/html/) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_HOST = site) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_USER_AGENT = Mozilla/5.0 (Windows NT 6.1; WOW64; rv:13.0) Gecko/20100101 Firefox/13.0) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_ACCEPT = text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_ACCEPT_LANGUAGE = en-us,en;q=0.5) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_ACCEPT_ENCODING = gzip, deflate) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_CONNECTION = keep-alive) [2012-06-06 23:50:52Z] Debug Read parameter. (HTTP_COOKIE = ASP.NET_SessionId=0176BE8FC161E702439D3C91) [2012-06-06 23:50:53Z] Debug Record received. (Type: StandardInput, ID: 1, Length: 0) [2012-06-06 23:50:53Z] Debug Record sent. (Type: EndRequest, ID: 1, Length: 8) I do not see what I am doing wrong. Any help would be great.