A 12.7.1 usually indicates a weather issue, either at the home location or the gateway, and it's usually intermittent. You've already rebooted the modem, which is the step I would suggest. You can also try power cycling the modem, which is unplugging the modem from the wall outlet, waiting for at least one minute, then plugging it back in. Then, after waiting for at least five minutes, try going online. If you're using a LAN cable connected computer, it's best to shut it down while performing the modem power cycle, then turn it back on after the aforementioned five minutes of waiting after plugging the modem back in. Power cycling can sometimes help where rebooting doesn't.
For reference, please do not reset the modem unless instructed to by a HughesNet rep, and then only in the manner they instruct, as doing so improperly, or in the wrong instance, can actually cause more harm than good. By "reset" I mean utilizing the reset button on the back of the modem.
If the problem continues the reps will likely have to help you. They're on M-F from approximately 9AM to 6PM EST, though there is occasionally one on in the evenings. They usually reply within a day. If you don't want to wait for help from them, you can call support at 866-347-3292.
If you do decide to wait, or even if you call, it would be best for you to leave your modem plugged in so that the reps can run remote diagnostics on your HughesNet equipment, if they deem it necessary (they likely will).