Hello!
I tried the replacing but no change. Neither was anything written to the file nor did I get any error messages. BUT:
With using this code
function onPaymentConfiguration(&$element) {
$this->writeToLog( 'test' );
}
I'm getting a almost blank page with the menu of HikaShop so I don't come onto the configuration page of the plugin (see attachment).
So I tried to add the code above into the existing
onPaymentConfiguration function but also no change of the report.log file (but at least I came onto the plugins configuration page).
After this I tried to manually write anything to the report.log file (via FTP) and view it via "configuration/files/view report" and it was still empty. Even after commenting out "deny from all" just to be sure it's not due to access restriction.