Your file is fine. Apple’s signature certificate has simply expired. Here is the industry-standard fix:
As the final point release of the 10.10 cycle, it contains all the security patches and bug fixes that the earlier versions lacked. Official Way to Download Yosemite 10.10.5
Select from the main menu, click Continue , and follow the setup instructions. Troubleshooting Common Installation Errors
Downloading requires specific steps because Apple no longer offers it directly on the main App Store front page. You can obtain a official DMG file from Apple's support servers or redownload the full installer if you have previously "purchased" it. 1. Official Download Links mac os x yosemite 10.10 5 download dmg
Go to your folder and double-click InstallMacOSX.dmg to mount the disk image.
Ensure your Mac is compatible before attempting an installation:
Improving synchronization issues with specific email servers. Photos App Stability: Enhancing the importing of videos from GoPro cameras. QuickTime Player: Fixing playback issues for Windows Media files. Security and Practicality Your file is fine
After downloading a DMG that contains the full installer app (e.g., Install OS X Yosemite.app ), you can use Apple's createinstallmedia command-line tool.
Mac OS X Yosemite 10.10.5 remains a landmark in Apple's history as the version that brought the "flatter," modern iOS aesthetic to the desktop. Whether you're reviving a classic machine or need it for specific legacy software, here is how to securely download and install it. The Direct Download Path
This indicates a corrupted download or an incomplete extraction. Delete the installer file from your Applications folder, re-download the DMG file using a stable wired connection, and re-extract the package. Official Way to Download Yosemite 10
Double-click the downloaded InstallMacOSX.dmg file to mount it. Open the mounted volume and double-click InstallMacOSX.pkg .
Type date 0101010115 and press (this sets the system date to January 1, 2015). Quit Terminal and try running the installation again. "Download Required File is Missing"