Developer Iron Studio games is urging players to back up their save data in Valheim as an “evil world-destroyer bug is still roaming free” in the popular game. “If you are playing Valheim this weekend, please backup your world and characters,” tweeted Iron Gate CEO, Richard Svensson, on Friday. “It’s an evil bug, that we have yet to be able to reproduce even once :(. It seems to occur more often if you exit the game by ALT+F4, so try to use menu -> exit instead,” Svensson notes. So, aside from exiting the game via navigating to the menu, you can also ensure you save your hard-earned in-game progress by backing up your data, too. As per the devs, players should find the game files; “in Windows, Worlds & characters are saved in C:\Users\Username\AppData\LocalLow\IronGate\Valheim". Back these up and keep them unless you’re affected by the bug (thanks, GamesRadar). If you have been hit by the world/character-deleting bug, all is not lost. Check the folder referenced above and you may find older, uncorrupted data. Look for the .db.old and .fwl.old files, and simply delete the .old in order to recover that data (per PC Gamer). Valheim is a survival game all about finding resources and crafting your own tools, and it can be quite tricky to get your head around. As such, you may want to know about repairing and maintaining your own lovingly handmade tools, defeating the first boss, finding the trader to purchase Ymir flesh, and – eventually – how to summon and beat the final boss.