Most of the time, if your controller isn't connecting to your Xbox One console, it's due to a networking problem.Ensure that your controller is positioned within 30 feet of the console, and that there's nothing blocking the signal.Also make sure that your Wi-Fi is working correctly — a buggy Wi-Fi router can sometimes interfere with other wireless signals in your house.The Xbox One can only support eight controllers at once.If your controller happens to be number nine, you'll need to disconnect at least one other controller before yours will work.If you've stepped away from your Xbox One for a while, the controller might have entered Sleep Mode to save battery.Try pressing and holding the Xbox button on the controller to turn it back on.If that doesn't work, the problem might be due to a drained battery. If you're using a wireless controller, try changing the batteries or connecting its charging cable. For an Xbox One Adaptive, which has a built-in battery, you only need to use it's USB-C cable to charge it.If you recently synced your Xbox One controller to another device, like an Android phone or tablet, you'll need to sync the controller and the Xbox One console once more.If you need a refresher on how to do this, check out our article on how to sync your Xbox One controller with your console. You can also sync the Xbox One Adaptive controller with the steps outlined in the article.Sometimes, simply starting and restarting the Xbox One can fix any issue that you're facing. Starting and restarting a device is called power cycling, and you can do that by pressing and holding the Power button on your console until it shuts down. Aftwards, simply turn the console back.You can also use an alternative method by reading our article on restarting an Xbox One.