Run Software Updates to ensure you have installed any pending updates.
Make sure there is enough free disk space, as 12 GB is required. Ensure your Mac meets the Diablo III System Requirements. Make sure you are logged on an administrator account on your Mac. Also, if you participated in the Diablo III beta, please make sure to uninstall the beta client before installing the retail version. Note: If you are receiving a specific error when attempting to install Diablo III (example: BLZPTS00007), search for the support article for that specific error and follow the relevant steps before trying the steps on this page. They are ordered from the most common at the top, to the less frequently needed at the bottom. The steps below are resolutions to installation issues with Diablo III.