Suitecrm page error.

Kindly help me resolve some error that i am getting when i try to load my suitecrm page.Below are the 3 errors i am getting .

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/pt/public_html/crm/config.php:1) in /home/pt/public_html/crm/config.php on line 2

Warning: Cannot modify header information - headers already sent by (output started at /home/pt/public_html/crm/config.php:1) in /home/pt/public_html/crm/include/utils.php on line 2698

I seem to have managed to get past the error above by saving the config.php file as utf uisng notepad ++ .But now after login in i cant access the admin function.All i am getting is the below error.Please help me resolve this since i already have active users on it but now they are locked out.

Fatal error: Tracker::get_recently_viewed(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "BreadCrumbStack" of the object you are trying to operate on was loaded before unserialize() gets called or provide a __autoload() function to load the class definition in /home/pt/public_html/crm/modules/Trackers/Tracker.php on line 108