Skip to:

Unknown character set error when importing from vBulletin 4.2.1

  • LTCOllie



    I’ve been attempting to import a vBulletin4.2.1 forum to bbPress 2.5.8 (running WordPress 4.4.2) and initially had database connection issues causing no users/posts/etc being found to covert. Having resolved the problems with these server import parameters I am now receiving an unknown character set error as below:

    Starting Conversion

    No users to convert

    WordPress database error: [Unknown character set: ‘utf8mb4’]
    SELECT convert(user.userid USING “utf8mb4”) AS userid,convert(user.password USING “utf8mb4”) AS password,convert(user.salt USING “utf8mb4”) AS salt,convert(user.username USING “utf8mb4”) AS username,convert( USING “utf8mb4”) AS email,convert(user.homepage USING “utf8mb4”) AS homepage,convert(user.joindate USING “utf8mb4”) AS joindate,convert(user.aim USING “utf8mb4”) AS aim,convert( USING “utf8mb4”) AS yahoo,convert(user.icq USING “utf8mb4”) AS icq,convert(user.msn USING “utf8mb4”) AS msn,convert( USING “utf8mb4”) AS skype FROM user AS user LIMIT 0, 100

    I’ve been trying the vBulletin importer rather than vBulletin3 having seen this advised elsewhere on this forum. Can anyone provide me with a solution/work around to prevent this issue?

    Thanks for the help!


Viewing 8 replies - 1 through 8 (of 8 total)
  • Hi Ollie,

    If you are starting from scratch with this, please consider going to bbPress 2.6. The import capabilities have improved a lot. You can download it from
    That version is very near to be launched to stable.




    Cheers for the info Pascal. I’ve installed bbPress bbPress 2.6 but unfortunately the problem persists. There is no table prefix used in the forum i am converting from so have left this field blank when attempting to convert. Is this acceptable? Thanks for the help! Ollie

    Could you please give me your PHP and MySQL version ?



    Here are the PHP/MySQL details of the server on which I am trying to access the existing forum database:

    Current PHP version: 5.3.3-7+squeeze13
    Server version: 5.0.51a-24+lenny4
    MySQL client version: 5.1.49

    It just so happens I get the following warning when I log onto phpmyadmin: ‘Your PHP MySQL library version 5.1.49 differs from your MySQL server version 5.0.51a. This may cause unpredictable behavior.’ Which could be a source of the problem?

    The server on which I am running my WordPress install and attempting to import the forum to is different and more up to date. Details below:

    Current PHP version: 5.4.45
    Server version: 5.5.45-cll-lve – MySQL Community Server (GPL)


    Hmmm, strange. I will have to read again, but if you only have 5.4.45 …



    Can anyone provide any further insight on this error?

    Thanks for the help so far!


    Any chance you could talk to your webhost and have the MySQL version updated?

    WordPress’ minimum requirements per are WordPress also works with PHP 5.2.4+ and MySQL 5.0+ which you are using but I suspect the phpMyAdmin warning Your PHP MySQL library version 5.1.49 differs from your MySQL server version 5.0.51a. you see are probably related to this issue.

    If your vBulletin database uses utf8_mb4 but your WordPress install is only using utf8 then you’ll run into issues. As Pascal pointed out with that link, you are using MySQL v5.0.x which doesn’t support utf8_mb4, only MySQL v5.5.3 and above does.

    If the vBulletin database used utf8 rather than utf8mb4 then I’d expect the import to work just fine, but because of the different character sets and collation differences the only way around this I see is to resolve this by upgrading to at least MySQL v5.5.3.



    Hi Stephen, Cheers for the reply!

    I’ve spoken with the host where the forum database I’ve been trying to import is located and they don’t anticipate being able to upgrade MySQL until the end of the year – It’s this kind of service that prompted me to move to a new host in the first place!

    With this not being an option I’m wondering if there is a way I can manually export the database to my new server running MySQL 5.3.3, manually update the database to utf8mb4 and retry the import from there. I’ve found an article at which appears to be along the right lines but might be a bit of a stretch for me as I’m pretty new to WordPress and coding. Does this seem like a sensible next step?

    Thanks for all the help and advice so far!

Viewing 8 replies - 1 through 8 (of 8 total)
  • You must be logged in to reply to this topic.
Skip to toolbar