I have created a yii app on a Mac with apache server(MAMP) and the app works fine , now I just switched to another machine with ubuntu 13.04 and apache server(LAMP) , and I copied what i developed on Mac to the new machine but nothing works , every time it gives server error with error code 500.
First try to find more information about the error. Usually your development machine should have error display enabled in php.ini and YII_DEBUG defined in index.php. That would make Yii display a full error message with a stack trace and also write it to the application.log.
Just remember not to enable this on the production machine.
When you encounter a serious error in PHP that prevents Yii for writing the log PHP usually leaves some information in the error log of your HTTP server.