To get around this annoying error, patrol each of the planets until you get into a patrol. Once you are in, you can go to orbit, then you will be able to enter the tower. If patrols do not work for you, you can also try weeklys/strikes. I personally tried hard resetting and it did not work. Also, quiting from the dashboard did not work. Up vote this so we can spread it to all guardians that are facing the same error. Hope this works for all!