how can I lock up a member list (addon - member list). I want, that member list can be shown only if administrator is log on (Only administrator can view a member list)

Administrator can view all members without a plugin. Go to Admin panel, choose "Search users" and don't specify anything, clicking the button. The list of all members will be shown.

thank you

is it possible that member list shown just for registered users?

Sure, use:

if($user_id>0) {memberslist block};

It's meant that you shall put this in addition to bb_plugins.php code :-)

I just found this in addon_members2.php

//Uncommenting the code below

and it works now..

thanks anyway..