You checked the key section of your inventory? Are you sure you tried clicking on the chest with the character that picked up the key?

Do you have a save before picking up the key, that you can reload and try the key again?


Please email supportdos@larian.com, with a description of the problem and the report.zip file generated by the D:OS support tool (for the PC version). The report will contain system and game information, any crash dumps, and your saved games (to reduce file size, you can delete all but your current save, and one from before picking up the key).