WARNING(2): "session_start(): Write of lock failed"

WARNING(2): "session_start(): Unable to clear session lock record"

WARNING(2): "session_start(): Cannot send session cookie - headers already sent by (output started at /var/www/gartenratgeber.de/html/gm/classes/ErrorHandler.php:380)"

WARNING(2): "session_start(): Cannot send session cache limiter - headers already sent (output started at /var/www/gartenratgeber.de/html/gm/classes/ErrorHandler.php:380)"

WARNING(2): "Cannot modify header information - headers already sent by (output started at /var/www/gartenratgeber.de/html/gm/classes/ErrorHandler.php:380)"

WARNING(2): "Unknown: Failed to write session data (memcached). Please verify that the current setting of session.save_path is correct (/var/www/gartenratgeber.de/html/cache/)"