Undefined array key "output"

[VMFnet]

While using econea/nusoap v0.9.17 under PHP 8.3, we encounter a lot of these warnings :

PHP Warning: Undefined array key "output" in /vendor/econea/nusoap/src/nusoap.php on line 4466
PHP Warning: Trying to access array offset on null in /vendor/econea/nusoap/src/nusoap.php on line 4466

It occurs in the parseRequest() method :

        // get/set custom response tag name
        $outputMessage = $this->wsdl->getOperationData($this->methodname)['output']['message'];

It seems that the ['output'] key of the array is not checked for existence before being accessed, therefore issuing these warnings.