"Failed to open descriptor file" on launch. Solution: The anti-virus (usually Windows Defender) quarantined the steam_api64.dll . Restore the file and add the entire game folder to the exclusions list.
Are you having the game or looking for a guide on a specific quest ? Dying Light 2 Stay Human v1.19.3-P2P
The primary focus of this hotfix was technical refinement rather than new content. According to the official patch notes , the update includes: "Failed to open descriptor file" on launch