protected function _checkErrors($iNavStep)
    {
        if ($iNavStep == 2) {
            if (!$this->_getUploadedCsvFilePath()) {
                $oEx = oxNew(\OxidEsales\Eshop\Core\Exception\ExceptionToDisplay::class);
                $oEx->setMessage('GENIMPORT_ERRORUPLOADINGFILE');
                \OxidEsales\Eshop\Core\Registry::getUtilsView()->addErrorToDisplay($oEx, false, true, 'genimport');

                return 1;
            }
        }

        if ($iNavStep == 3) {
            $blIsEmpty = true;
            $aCsvFields = \OxidEsales\Eshop\Core\Registry::getConfig()->getRequestParameter('aCsvFields');
            foreach ($aCsvFields as $sValue) {
                if ($sValue) {
                    $blIsEmpty = false;
                    break;
                }
            }

            if ($blIsEmpty) {
                $oEx = oxNew(\OxidEsales\Eshop\Core\Exception\ExceptionToDisplay::class);
                $oEx->setMessage('GENIMPORT_ERRORASSIGNINGFIELDS');
                \OxidEsales\Eshop\Core\Registry::getUtilsView()->addErrorToDisplay($oEx, false, true, 'genimport');

                return 2;
            }
        }

        return $iNavStep;
    }