In the CI (codeigniter) framework, routes. php is correctly set, but the server is abnormal. it indicates that _ construct has less underline.

CI (codeigniter) framework, routes. the php settings are correct, but the server error is displayed. it means _ construct writes less than one underline. today, I got a CI framework. after reading about the documentation, I feel that the CI framework is very streamlined, however, I encountered a problem when doing this. the CI document provides an example of a News system. all the work is done. open the corresponding url in the browser: CI (codeigniter) framework, routes. php settings are correct, but server errors are displayed. _ construct writes less underline
Today, I got a CI framework. after reading about the documentation, I felt that the CI framework was very simple, but I encountered a problem. The CI documentation provides an example of a News system, after all the work is done, the corresponding url is opened in the browser, but the "server error" is displayed, with no prompt at all. opening firebug shows the error code for error connection 500, at this time, the log under the application under the CI framework is opened, but some useful information is not provided. Finally, the appache errr_log is opened. the _ construct problem is displayed here. I open the corresponding php file, is parent ::__ construct with less underline