CakePHP会话与Mac和Windows之间的区别

I am using cakePHP 2.4 on windows running WAMP with no issues.

As soon as I move the source code over to Mac running WAMP I get errors regarding the headers being already sent.

Has anyone come across this before?

Warning (2): session_start(): Cannot send session cache limiter - headers already sent (output started at /Applications/MAMP/htdocs/cskplay/app/Controller/UsersController.php:2) [APP/Vendor/facebook-php-sdk-master/src/facebook.php, line 49]

I have already tried everything in this post:

CakePHP 2.x sessions behaving inconsistently between local dev and production

Fixed! It was an empty line between the start of a controller and the opening <?.

strange how it only mattered on Mac not windows.