Warning: PHP Request Startup: Invalid date.timezone value 'Avrupa / Istanbul', using 'UTC' instead in Unknown on line 0

Warning: PHP Request Startup: Session ini settings cannot be changed after headers have already been sent in Unknown on line 0
Error: Failed to start application: Failed to start the session because headers have already been sent by "" at line 0.
Warning: PHP Startup: Invalid date.timezone value 'Avrupa / Istanbul', using 'UTC' instead in Unknown on line 0