The function bb2_table_structure moved to bad-behavior-mysql.php. This file is missing (and not included) in the bb2 plugin.
As long as you are upgrading, you're fine, since the table did not change, though there is a second function that creates log file entries (and probably missing too?):
PHP Formatted Code
cannot show the code since a server error pops up persistently
// Insert a new record
bb2_insert($settings, $package, $key)