It’s easy, particularly when traveling, to end up connecting to a Wi-Fi network that doesn’t provide Internet access (such as AMC Theaters Porter Ranch!), that requires credentials you don’t have, or lacks access to the network’s printer. Unfortunately, once your iPhone, iPad, or Mac has connected to such a network, it may reconnect to it later, causing consternation when things don’t work. The solution? Whenever you realize a Wi-Fi network is worthless, forget it. (The network, that is.) On the Mac, open System Preferences > Network > Wi-Fi > Advanced > Wi-Fi, select the network in the list (you don’t have to be connected to it), click the – button, and click Remove. On an iPhone or iPad, when you’re connected to the offending network, go to Settings > Wi-Fi, tap the i button to the right of the current network, and tap Forget This Network on the next screen. We recommend doing this every few months.