WP_w3all for WordPress MS MU (Multisite, Multiuser network installations)

Configure WP_w3all on WordPress MS MU

WP_w3all plugin from 2.0.2 – WordPress MU MS  . The plugin can be also network activated, but the linked phpBB on each subsite, need to be the same (same path and same url setting value). If the plugin is network activated, it is mandatory that the sub admin or super admin, setup/configure  into (each) subsite the same config of the main site for the integration plugin. Users that register in phpBB (if you allow this in phpBB) are added as users only into the FIRST WP site (or subsite) where users will login or that they will visits while coming already logged in into phpBB. *But you could use a plugin to add coming phpBB logged users, into each or just few WordPress site/subsites they visits.

OPEN wp-config.php file:

search for line (value wp_ could be different):

immediately after ADD:

NOTE since 2.7.9>

If you want the phpBB users additions in WordPress allowing all default WP characters for the WordPress usernames, add the follow:

adding the above, allowed characters for WordPress usernames that are added in WordPress from phpBB, becomes:

so alphanumeric characters (letters and numbers) spaces, underscores, hyphens, periods, and @

The default WP MUMS normally and by default only allow the range

so only alphanumeric characters

BEWARE that it is NOT possible to link different phpBB installations on same installation network, the integration in this state lead to unpredictable results.
Setup into each sub-site, same configuration values of the main site.

NOTE: WP_w3all phpBB integration plugin when an user is deleted in WordPress (so maybe it will be deleted in phpBB also) go to immediately clean up this user from the signup table in WordPress. This is necessary for compatibility with the phpBB integration, in case it’s allowed to register users in phpBB, and an user has been also deleted in phpBB while the user has been deleted in WP, but the email/username still exists stored into the WP database signups for some while, when on mums (or using plugins like buddypress etc).