Go to Moderator Control Panel -> User Notes -> Find a member -> select member. It will not work because "form" is not being passed in the URL: http://localhost/memberlist.php?mode=searchuser&field=username" target="_blank

Fix in includes/mcp/mcp_notes.php
Find:

'U_FIND_MEMBER'		=> "memberlist.$phpEx$SID&mode=searchuser&field=username",

Replace with:

'U_FIND_MEMBER'		=> "memberlist.$phpEx$SID&mode=searchuser&form=mcp&field=username",

Thanks.