A bug in the Fallout 76 beta launcher would cause the game to delete itself. After instructing gamers to "not click any buttons," Bethesda admitted the bug and instructed affected players to re-download the 50 GB title. In an effort to make good with its playerbase, Bethesda extended the beta to include this Thursday, November 1, from 2 PM to 11 PM.
https://www.notebookcheck.net/Do-not-click-any-buttons-Bug-in-Fallout-76-beta-nukes-the-entire-game-from-your-hard-drive.354641.0.html