Check that the configuration mode is no longer activated: the indicator lights on the wired products must be off. If this is not the case, press and hold the center of the master switch briefly then release, or via the EZ button on the smart gateway. The indicator lights on the wired products will turn off. Make sure that the gateway power outlet or the gateway module is correctly powered and that your smartphone has an adequate Wi-Fi signal. Then click on "try again" on the pop-up error message that appears. If the signal quality is poor, you may be able to see a product after up to 10 seconds.
If you still have trouble, you will be able to place the products manually later, from the App settings, by selecting "Manage my home", "Products not placed".