We are aware of some customers using Mac OS receiving an error message when they attempt to open the Steam application installer. Normally, the package should open and present you with a graphic allowing you to drag the Steam application icon to your Applications folder. In some cases, however, it can interact with certain versions of Mac OS and give an error message about a "damaged package". This can happen with other installers as well. If you encounter this message, here are the steps you should follow:
- Confirm you've downloaded the correct version for your computer, and it's compatible with your system
- Check for any updates to your OS
- Redownload the package from Steam's website in case of any interruption in the download that could have corrupted the file
- If you still see this error, control-click (or right click) on the steam.dmg image and select "Open" instead of double-clicking
Please be aware this is not a defect with our product. Steam is a third-party application, and if these steps do not work for you, we suggest you contact Steam's customer support.