Error: Cannot connect to MySQL database

Hi,

I have a BackWPup scheduled on a client’s site to backup the database and web files to DropBox. Recently though I’ve been getting error messages with regard to connecting to MySQL and the database backup has failed. Below is the error message I get. What can I do to fix this?

[27-Mar-2013 03:13:56] WARNING: mysqli::mysqli() [<a href='mysqli.mysqli'>mysqli.mysqli</a>]: Premature end of data (mysqlnd_wireprotocol.c:553)
[27-Mar-2013 03:13:56] WARNING: mysqli::mysqli() [<a href='mysqli.mysqli'>mysqli.mysqli</a>]: OK packet 1 bytes shorter than expected
[27-Mar-2013 03:13:56] WARNING: mysqli::mysqli() [<a href='mysqli.mysqli'>mysqli.mysqli</a>]: (HY000/2000): mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool to reset your password with the command SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, and more secure, hash value in mysql.user. If this user is used in other scripts executed by PHP 5.2 or earlier you might need to remove the old-passwords flag from your my.cnf file
[27-Mar-2013 03:13:56] ERROR: Cannot connect to MySQL database 2000: mysqlnd cannot connect to MySQL 4.1+ using the old insecure authentication. Please use an administration tool to reset your password with the command SET PASSWORD = PASSWORD('your_existing_password'). This will store a new, and more secure, hash value in mysql.user. If this user is used in other scripts executed by PHP 5.2 or earlier you might need to remove the old-passwords flag from your my.cnf file

Thanks

Rob

https://www.ads-software.com/extend/plugins/backwpup/