Article ID: 112521, created on Oct 13, 2011, last review on May 11, 2014

  • Applies to:
  • Plesk for Windows


When you log in to Parallels Plesk Panel (PP) via https://host:8443/, you can see an error message like the folowing:

ERROR: PleskMainDBException 
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

You may also encounter this error during a PP upgrade procedure.


There is an incorrect version of the libmySQL.dll library in the folder:
for x32 OSes - C:\windows\system32\
for x64 OSes - C:\windows\SysWOW64\

The library may have been replaced by some third-party software if it was installed to the server.


Before upgrading, we strongly recommend replacing the libmySQL.dll library with the version which was installed during Parallels Plesk Panel installation. You can create a backup of the current version of libmySQL.dll and replace it with the attached file.


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