@timmalos Probably the simplest solution is to manually run Firefox with the "--marionette" option and then connect to this browser with the following -- _WD_Option('Driver', 'geckodriver.exe') _WD_Option('DriverParams', '--log trace --connect-existing --marionette-port 2828') _WD_Option('Port', 4444) Local $sDesiredCapabilities = '{"desiredCapabilities":{"javascriptEnabled":true,"nativeEvents":true,"acceptInsecureCerts":true}}' _WD_Startup() $sSession =