500内部服务器错误 - dojo.js或我的PHP文件？

I have sort of problem. It is 500 Internal Server Error.

This happened during my development. I could not figure what caused the problem. I am using dojo, php and pdo. Please see the red circles as indicated in the pictures below. These circles indicate my php file, dojo.js and selected item indicated. It happened when I selected one of the items in the dojo comboBox.

Can you point me to the root of the problem?

Your test_MkTests.php page and its javascript loads fine.
Then javascript calls gatherbaches.php but http server gives 500 internal server error. Check your gatherbaches.php, php_error.log and http server error log. Check your FirePHP.class.php ( 612 line )

Try load gatherbaches.php directly in browser to check it is working.