When using a Cookie-Consent-Tool you have to use a timeout for enabling cookies, because the eTracker-Script is loaded asynchronous and thus the relevant script-methods won't be available directly.
Example:
function waitForEtracker(){
if(typeof _etracker !== "undefined"){
_etracker.enableCookies(rkwEtrackerDomain);
console.log('eTracker: cookies enabled');
} else{
setTimeout(waitForEtracker, 250);
}
}
waitForEtracker();