常量CAKE_CORE_INCLUDE_PATH已定义CakePHP

Question

I am a beginner to CakePHP, I just got a code of the project to make some minor changes into the project, but as I copy and paste the project files into my wamp server and changed my database constants according to my localhost, I got error and website site is not even loading properly no css no js.

I am using 2.5 CakePHP Version and 5.6 PHP version

The complete error message is

( ! ) Notice: Constant CAKE_CORE_INCLUDE_PATH already defined in C:\wamp64\www\cakephp2.5\app\webroot\index.php on line 64
Call Stack
#   Time    Memory  Function    Location
1   0.0007  242672  {main}( )   ...\index.php:0
2   0.0015  265256  require( 'C:\wamp64\www\cakephp2.5\app\webroot\index.php' ) ...\index.php:41
3   0.0015  265488  define ( )  ...\index.php:64

Thanks