Installing El Capiton on an old Mac Book Pro today, I received the error:
OS X could not be installed on your computer
No packages were eligible for install. Contact the software manufacturer for assistance.
Quit the installer to restart your computer and try again.
I checked Apple’s support Matrix (it is a very old macbook pro) at https://support.apple.com/kb/SP728?locale=en_GB and it was listed as supported.
After lots of Googling and investigation, I discovered that the date and time were not set to current, the macbook thought it was year 2000.
You can easily reset the time and date by following the steps below:
- Click Utilities on the menu bar
- Select Terminal
- Type date
- Confirm the date is wrong
- Type date 062112422016 (example: June 21st 12:42 2016)
- Exit terminal
- Click Restart
Once the Date and time are configured you will be able to install OS X.
Easy fix, for a ridiculous error!