[TYPO3-seminars] Fatal error after upgrading T3 and seminars

[Jürgen Novotny]

Hi,

just upgraded a TYPO3 v 4.2 installation to v. 4.5.15, updated seminars to 0.9.3 (ameos_formidable 1.1.373, oelib 0.7.7) and installed onetimeaccount 0.8.0. Everything works fine when choosing a seminar, filling in the onetimeaccount data and the "Anmeldung Schritt 1 von 2". When sending the registration on page 2 from now on I receive a fatal error (Fatal error: Call to a member function getAttendancesPid() on a non-object in /html/typo3conf/ext/seminars/class.tx_seminars_seminar.php on line 3285). I just can't find the error since everything worked fine in the old version (only with felogin, which currently gives the same fatal error, so it seems to not depend on onetimeaccount).

The affected code in class.tx_seminars_seminar.php:

public function getAttendancesPid() {
		if (!$this->hasOrganizers()) {
			return 0;
		}

		$organizers = $this->getOrganizerBag();
		$firstOrganizer = $organizers->current();
		$organizers->__destruct();

		return $firstOrganizer->getAttendancesPid();   <- line 3285
		
	}

Any hints?
Thanks,
Flynn