Cannot download the OS X El Capitan
After I click the DOWNLOAD button in App Store, the loading icon on the left top corner start rotating, but I get an error message finally.
I have tried the above process many times and the results are the same.
About my iMac:
iMac (21.5-inch, Late 2012)
2.9 GHz Intel Core i5
8 GB 1600 MHz DDR3
iOS 10.10.5
App Store version 2.0
iPhone 6 Plus, iOS 9.1