Hello there, Thank you very much for reaching out to us. I'm sorry to hear that all of your activities seem to have disappeared along with the quest. We've received reports of this issue and are investigating the underlying issue further. For any updates on this issue, we recommend viewing our [url=http://www.x.com/Destiny2Team]X/Twitter page[/url] and our Patch Notes as they become available, posted on the [url=https://www.bungie.net/7/en/News]News page[/url]. In the meantime, a workaround that has helped some players is to change your faction (if the option is available(there's a maximum you can change daily)), abandoning The Territory War Begins quest (which it seems to have already been removed), and then reacquiring it from the Tharsis Outpost.