[MoT3rror]

I am not for sure if this will work. I would test this on a development server before trying.

Using one the register hooks. Change the current DB info using this code assign the correct values for the second site.

PHP Code:

$db->connect(
    $vbulletin->config['Database']['dbname'],
    $vbulletin->config['MasterServer']['servername'],
    $vbulletin->config['MasterServer']['port'],
    $vbulletin->config['MasterServer']['username'],
    $vbulletin->config['MasterServer']['password'],
    $vbulletin->config['MasterServer']['usepconnect'],
    $vbulletin->config['SlaveServer']['servername'],
    $vbulletin->config['SlaveServer']['port'],
    $vbulletin->config['SlaveServer']['username'],
    $vbulletin->config['SlaveServer']['password'],
    $vbulletin->config['SlaveServer']['usepconnect'],
    $vbulletin->config['Mysqli']['ini_file'],
    $vbulletin->config['Mysqli']['charset']
); 


Then in the same hook use the user datamanager to create a user on the other site.
https://vborg.vbsupport.ru/showthrea...t=create+users

Then switch the DB info back to the current site.

PHP Code:

$db->connect(
    $vbulletin->config['Database']['dbname'],
    $vbulletin->config['MasterServer']['servername'],
    $vbulletin->config['MasterServer']['port'],
    $vbulletin->config['MasterServer']['username'],
    $vbulletin->config['MasterServer']['password'],
    $vbulletin->config['MasterServer']['usepconnect'],
    $vbulletin->config['SlaveServer']['servername'],
    $vbulletin->config['SlaveServer']['port'],
    $vbulletin->config['SlaveServer']['username'],
    $vbulletin->config['SlaveServer']['password'],
    $vbulletin->config['SlaveServer']['usepconnect'],
    $vbulletin->config['Mysqli']['ini_file'],
    $vbulletin->config['Mysqli']['charset']
); 


There might be better way to do this but I am just giving a idea. Also there might be more to this then just this code.