Странная "ошибка при обработке запроса"

server {
    listen 80;
        server_name firmware;
        charset utf-8;
        access_log  /var/log/nginx/firmware.access.log;
        error_log  /var/log/nginx/firmware.error.log  warn;

        client_max_body_size 1m;

        set $www_root "/Users/user/www/firmware/www";
        location ~* ^.+\.(jpg|jpeg|gif|png|ico|css|zip|tgz|gz|rar|bz2|doc|xls|exe|pdf|ppt|txt|tar|wav|bmp|rtf|js)$ {
            root $www_root;
        }
        location ~ /\.ht {
                deny all;
        }
        location / {
               proxy_pass http://127.0.0.1:88;
               proxy_set_header Host $host;
        }

}

{"message":"<div id=\"tableslistcontainer\"><form method=\"post\" action=\"db_structure.php\" name=\"tablesForm\" id=\"tablesForm\"><input type=\"hidden\" name=\"db\" value=\"serials\" \/><input type=\"hidden\" name=\"token\" value=\"6150cc17d8d299b67ce1142474b9b047\" \/><table class=\"data\">\n<thead>\n<tr><th><\/th>\n<th>\n<a href=\"db_structure.php?db=serials&amp;token=6150cc17d8d299b67ce1142474b9b047&amp;pos=0&amp;sort=table&amp;sort_order=DESC\" title=\"\u041e\u0442\u0441\u043e\u0440\u0442\u0438\u0440\u043e\u0432\u0430\u0442\u044c\" onmouseover=\"$('.sort_arrow').toggle();\" onmouseout=\"$('.sort_arrow').toggle();\">\u0422\u0430\u0431\u043b\u0438\u0446\u0430 <img src=\"themes\/dot.gif\" title=\"\" alt=\"\u041f\u043e \u0432\u043e\u0437\u0440\u0430\u0441\u0442\u0430\u043d\u0438\u044e\" class=\"icon ic_s_asc sort_arrow\" \/> <img src=\"themes\/dot.gif\" title=\"\" alt=\"\u041f\u043e \u0443\u0431\u044b\u0432\u0430\u043d\u0438\u044e\" class=\"icon ic_s_desc sort_arrow hide\" \/><\/a>\n<\/th>\n<th colspan=\"6\">\n        \u0414\u0435\u0439\u0441\u0442\u0432\u0438\u0435\n<\/th><th>\n<a href=\"db_structure.php?db=serials&amp;token=