Error when canceling CiviMail mailing after test message sent successfully

When creating a CiviMailing completing test message and sent successfully, If you choose cancel button on the page the following page was returned on : /civicrm/mailing/send

Send Mailing

unrecoverable error
Sorry. A non-recoverable error has occurred.

Return to CiviCRM menu.

error

Array
(
[callback] => Array
(
[0] => CRM_Core_Error
[1] => handle
)

[code] =>
[message] => HTML_QuickForm_Controller: Unhandled action "Cancel" in page "Schedule"
[mode] => 16
[debug_info] =>
[type] => PEAR_Error
[user_info] =>
[to_string] => [pear_error: message="HTML_QuickForm_Controller: Unhandled action "Cancel" in page "Schedule"" code=0 mode=callback callback=CRM_Core_Error::handle prefix="" info=""]
)