Monster Hunter World fans found their save files deleted after the Iceborne update launched last night.

After dropping for console players in September, Monster Hunter World’s latest DLC finally made it to PC this week. PC fans that waited eagerly for the release were treated with a distressing surprise. Iceborne’s update couldn’t find a save file. And if they continued the game, it would delete their save file completely.

First reported by VG24/7, upon logging in, players were met with an error message reading “no compatible save file found.” If players enabled cloud saving, continuing the game would delete the file in the cloud permanently. And since it’s an odd, confusing situation, it’s easy to continue and find your data gone. Monster Hunter World is a game that takes hundreds of hours to grind and gather items and complete. Losing a save file is devastating for the file owner.

There are a lot of theories about why it happened. Some say mods, and some say if you haven’t logged in a while, it caused it because there was a transfer that occurred.

According to Gosunoob, developers changed the way files were read and saved, and is considered the main issue. If you haven’t played in a while, you may have missed this conversion.

If it hasn’t happened to you, make a backup of your files and store it someplace safe, just in case. You probably won’t need to worry if it hasn’t already hit, but best to protect that save data anyway.

If you have seen that dreaded error message, do not proceed with the game until you do so, your files are still there; the game just can’t read them. Gosunoob suggests you wait for a developer to fix or load up the base game with the DLC disabled. That may convert the files, and then you’ll be able to load Iceborne.

If you have already started a new file, Gosunoob suggests your old one may still be in your Steam folder on your PC and might be recovered there.