好的，这个问题的根源是使用mysql_connect连接到数据库时出错。由于某种原因，它不会产生任何错误，也不会产生 or die（ error ...）;的任何错误；这是因为我们在服务器上使用的是php 5.4，并且似乎不再支持mysql_connect ，除非您已安装mysqlnd，解决方案是将数据库驱动程序切换为CodeIgniter幸运地具有该驱动程序的'mysqli'，然后使用以下命令安装php5-mysql：apt-get install php5-mysql
希望这会有所帮助其他人。

Okay, the root of this problem was an error connecting to the database using mysql_connect. For some reason, it would not produce any error whatsoever, nor would "or die("error..."); do anything. This was because we were using php 5.4 on the server, and mysql_connect does not seem to be supported anymore, unless you have mysqlnd installed. The solution was to switch our database driver to 'mysqli', which CodeIgniter luckily has a driver for, and then install php5-mysql with: apt-get install php5-mysql Hope this helps anyone else.