Unsupported operand types: string & int (DataHandler.php)

[mminyades]

When attempting to import datasets of the extension "tx_news" (tx_news_domain_model_news), I receive several errors related to "DataHandler.php"

Unsupported operand types: string & int
...sysext/core/Classes/DataHandling/DataHandler.php line 2313

No data is imported.

(TYPO3 12.4.11 / News 11.4.1)

[nevaf]

Same Error with 11.5.31
Unsupported operand types: string / int
in ypo3_src-11.5.31/typo3/sysext/core/Classes/DataHandling/DataHandler.php line 1200
if ($sortColumn) {
$fieldArray[$sortColumn] = $this->getSortNumber($table, 0, $pid);
}
then this is executed in
/typo3_src-11.5.31/typo3/sysext/core/Classes/DataHandling/DataHandler.php line 771
return floor($row[$sortColumn] / 2);

How can I prevent this?