Mysqli error

Hi
The website is getting the following errors on www.kevinkirby.com:

Warning: mysqli::mysqli(): Headers and client library minor version mismatch. Headers:50542 Library:50635 in /home/kevinkir/public_html/system/library/db/mysqli.php on line 7
Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /home/kevinkir/public_html/system/library/db/mysqli.php:7) in /home/kevinkir/public_html/system/library/session.php on line 21Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /home/kevinkir/public_html/system/library/db/mysqli.php:7) in /home/kevinkir/public_html/system/library/session.php on line 21Warning: Cannot modify header information - headers already sent by (output started at /home/kevinkir/public_html/system/library/db/mysqli.php:7) in /home/kevinkir/public_html/index.php on line 189Warning: Cannot modify header information - headers already sent by (output started at /home/kevinkir/public_html/system/library/db/mysqli.php:7) in /home/kevinkir/public_html/system/storage/modification/system/library/currency.php on line 45

I have tried to search for an answer on web but none of the solutions found work or rely on the host server to be changed. Has anyone else seen this error and what has caused it? Grateful for any help.
Subatwest

hosting/database problem.
your hosting probally upgraded your sql engine.
only follow this if youre comfortable with it.
backup your database using phpmyadmin.
remove database from hosting
remove user
recreate database and user
reimport database.

Many thanks. You were right Hosting changed their side now sorted..