Stylesheet not parsed because non CSS MIME types are not allowed in strict mode

Question

I am getting the following error on my site:

[Error] Did not parse stylesheet at 'http://test.opendialogueapproach.co.uk/wp-content/plugins/revslider/public/assets/css/settings.css?ver=5.2.5.3' because non CSS MIME types are not allowed in strict mode.

Having done some research it seems that this is probably related to my nginx configuration, but my nginx files seem to be structured rather different to those I have seen elsewhere, so I'm not sure what changes are needed to fix the issue. I am including the three nginx files that seem relevant below:

first the mime.conf file in etc/nginx then the nginx.conf, also in etc/nginx and finally the conf file for my site in etc/nginx/conf.d

mime.conf

types {
    text/html                             html htm shtml;
    text/css                              css;
    text/xml                              xml rss;
    image/gif                             gif;
    image/jpeg                            jpeg jpg;
    application/x-javascript              js;
    text/plain                            txt;
    text/x-component                      htc;
    text/mathml                           mml;
    image/png                             png;
    image/svg+xml                         svg svgz;
    image/x-icon                          ico;
    image/x-jng                           jng;
    image/vnd.wap.wbmp                    wbmp;
    application/java-archive              jar war ear;
    application/mac-binhex40              hqx;
    application/pdf                       pdf;
    application/x-cocoa                   cco;
    application/x-java-archive-diff       jardiff;
    application/x-java-jnlp-file          jnlp;
    application/x-makeself                run;
    application/x-perl                    pl pm;
    application/x-pilot                   prc pdb;
    application/x-rar-compressed          rar;
    application/x-redhat-package-manager  rpm;
    application/x-sea                     sea;
    application/x-shockwave-flash         swf;
    application/x-stuffit                 sit;
    application/x-tcl                     tcl tk;
    application/x-x509-ca-cert            der pem crt;
    application/x-xpinstall               xpi;
    application/zip                       zip;
    application/octet-stream              deb;
    application/octet-stream              bin exe dll;
    application/octet-stream              dmg;
    application/octet-stream              eot;
    application/octet-stream              iso img;
    application/octet-stream              msi msp msm;
    audio/mpeg                            mp3;
    audio/ogg                             oga ogg;
    audio/wav                             wav;
    audio/x-realaudio                     ra;
    video/mp4                             mp4;
    video/mpeg                            mpeg mpg;
    video/ogg                             ogv;
    video/quicktime                       mov;
    video/webm                            webm;
    video/x-flv                           flv;
    video/x-msvideo                       avi;
    video/x-ms-wmv                        wmv;
    video/x-ms-asf                        asx asf;
    video/x-mng                           mng;
}

nginx.conf

user www-data www-data;
pid /var/run/nginx.pid;
worker_processes 2;
worker_rlimit_nofile 100000;

events {
    worker_connections  4096;
    include /etc/nginx.custom.events.d/*.conf;
}

http {
    default_type application/octet-stream;

    access_log off;
    error_log  /var/log/nginx/error.log crit;

    sendfile on;
    tcp_nopush on;

    keepalive_timeout 20;
    client_header_timeout 20;
    client_body_timeout 20;
    reset_timedout_connection on;
    send_timeout 20;

    types_hash_max_size 2048;

    gzip on;
    gzip_disable "msie6";
    gzip_proxied any;
    gzip_min_length 256;
    gzip_comp_level 4;
    gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript application/javascript text/x-js;

    server_names_hash_bucket_size 128;

    include mime.conf;
    charset UTF-8;

    open_file_cache max=100000 inactive=20s;
    open_file_cache_valid 30s;
    open_file_cache_min_uses 2;
    open_file_cache_errors on;

    server_tokens off;
    ssl_protocols TLSv1 TLSv1.1 TLSv1.2;

    include proxy.conf;
    include fcgi.conf;

    include conf.d/*.conf;
    include /etc/nginx.custom.d/*.conf;
}

include /etc/nginx.custom.global.d/*.conf;

Site conf file:

server {
    listen *:80;


    server_name test.opendialogueapproach.co.uk;

    access_log /var/log/nginx/testopendialogueapproachcouk.access.log;
    error_log /var/log/nginx/testopendialogueapproachcouk.error.log;

    root /var/www/opendialogueapproach.co.uk/test/html;
    index index.html index.htm index.php;

    location / {
        try_files $uri $uri/ /index.php?q=$request_uri;
}

location /wp-content/uploads/bp-attachments/ {
    rewrite ^.*uploads/bp-attachments/([0-9]+)/(.*) /?p=$1&bp-attachment=$2 permanent;
}



    location ~ [^/]\.php(/|$) {



        fastcgi_index index.php;
        include fcgi.conf;
        fastcgi_pass unix:/var/run/ajenti-v-php-fcgi-testopendialogueapproachcouk-php-fcgi-0.sock;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

    }

}

Answer 1

Note that you'll get that error if the page doesn't exist and your server is set to fallback or show some error page for non-existent pages.