I am jumping on this as well, I have exact same issue with the missing mystery file right after the update with my Win 7 Pro. I have had Destiny 2 for ages but just started really getting into it the last week as we are in hard lockdown here in Australia. So now a game I have put hours into the the past few days is unplayable, not to mention the 4 hours today for a reinstall and trying all the other bogus suggestions. Come on Bungie I was gonna purchase all the upgrades now I have a love for he game, but now ??? Have a heart for those in lockdown and need a diversion and fix this problem!!