Merging two vB4.2.1 forum ---database error

[Mark.B]

Hello
I am going to merge two forums in to one forum, i want move threads and posts from one vBulletin to another, how i can do it? should i use IMPEX?
Both forum are vBulletin 4 Version.
Thanks

Please start your own topic with full details of the issue. Thank you.

[pcmwebmaster]

Hello
I am going to merge two forums in to one forum, i want move threads and posts from one vBulletin to another, how i can do it? should i use IMPEX?
Both forum are vBulletin 4 Version.
Thanks

[Trevor Hannant]

Resolved via ticket - the prefix was missing from the ImpexConfig.php file.

[BirdOPrey5]

Make sure you are connected to the correct database Also make sure you have set the correct table prefix for your import database, if the old database had a table prefix you need to set it in the impex config file.

If you're not sure, open the import database in phpmyadmin- if all the tables have a prefix before them, like vb_datastore then vb_ is the prefix.

[Kwak]

Have a forum running 4.2.1 and using Impex to import another database to merge into the 1st forum.

After the initial Import error using Impex,

ImpEx build version : 1.104  Database cleanup & restart |||  Online manual  
Using includes/config.php for target config. 

I click Database cleanup & restart

Cancel
To cancel and return to the import, click here.

Delete Session
To delete the import session and continue with the import, click here.

Delete Session and all imported data
FORUM data - To delete the import session and all imported data for a clean retry, click here.

CMS data - To delete the import session and all imported data for a clean retry, click here.

BLOG data - To delete the import session and all imported data for a clean retry, click here.

Remove Importids
FORUM importids - To delete the importids in the database, click here, also removes the session. This will allow you to do consecutive imports

CMS importids - To delete the importids in the database, click here, also removes the session. This will allow you to do consecutive imports

BLOG importids - To delete the importids in the database, click here, also removes the session. This will allow you to do consecutive imports

Remove duplicate forums/threads/posts.
This will remove anything that has a duplicate importid and a diffrent vBulletin id. Use with EXTREME caution, results will vary between source systems, ALWAYS TAKE A BACK UP BEFORE USING 

Clicking on any of the link gives me:

ImpEx Database error

mysql error: Invalid SQL: DELETE FROM datastore WHERE title='ImpExSession';

mysql error: Table 'database_dbname.datastore' doesn't exist

mysql error number: 1146

Date: Thursday 09th 2013f May 2013 10:02:55 PM
Database: database_dbname
MySQL error: Table 'database_dbname.datastore' doesn't exist 

What could be the problem? Thank you.
I am a novice when it comes to mysql database.