After I updated to Moodle 2.3 (20120612) I get the following error on the admin notification page moodle/admin/index.php

Coding error detected, it must be fixed by a programmer: PHP catchable fatal error

More information about this error

Debug info: Argument 2 passed to available_update_info::__construct() must be an array, string given, called in /Library/Server/Web/Data/Sites/Default/moodle/lib/pluginlib.php on line 718 and defined
Error code: codingerror
Stack trace:
line 397 of /lib/setuplib.php: coding_exception thrown
line 1367 of /lib/pluginlib.php: call to default_error_handler()
line 718 of /lib/pluginlib.php: call to available_update_info->__construct()
line 1705 of /lib/pluginlib.php: call to available_update_checker->get_update_info()
line 127 of /lib/pluginlib.php: call to plugininfo_base->check_available_updates()
line 964 of /lib/pluginlib.php: call to plugin_manager->get_plugins()
line 707 of /lib/pluginlib.php: call to available_update_checker->load_current_environment()
line 429 of /admin/index.php: call to available_update_checker->get_update_info()