Trying to install older OS's

[Dopeyman]

I'm want to install either Mavericks or Yosemite on an older iMac. But I'm getting those errors before it starts installing. Does that mean that Apple is no longer supporting them? These files are the ones I downloaded from the App Store when they first came out and they installed fine.

Is there any way around these errors?

 

[CoastalOR]

If you downloaded the installers before 14 Feb. 2016 then the certificate has expired. You will need to re-download the installers from the App store or change the date to use the old installer.

https://tidbits.com/2016/03/02/previously-downloaded-os-x-installers-no-longer-work/

 

[Fishrrman]

A trick that might work:
Reset the Mac's internal clock to an older date, say, 2012.
Make sure the clock is set to NOT obtain current time from the net.
Then, reboot and try the installer again.

No promises, might not work.
But... worth trying.

 

[Dopeyman]

If you downloaded the installers before 14 Feb. 2016 then the certificate has expired. You will need to re-download the installers from the App store or change the date to use the old installer.

https://tidbits.com/2016/03/02/previously-downloaded-os-x-installers-no-longer-work/

Thank you for the info. I went back to the App Store and re-downloaded the installers. That did the trick. They worked. Thank you.

A trick that might work:
Reset the Mac's internal clock to an older date, say, 2012.
Make sure the clock is set to NOT obtain current time from the net.
Then, reboot and try the installer again.

No promises, might not work.
But... worth trying.

I re-downloaded. That worked. Thank you for your input.

 

[MIKX]

Boot from a USB Mavericks or Yosemite installer stick or from Recovery.

Start Terminal

For Mavericks Enter date 110216472913.53

For Yosemite Enter date 1020133015

Then install.

 

[Dopeyman]

Boot from a USB Mavericks or Yosemite installer stick or from Recovery.

Start Terminal

For Mavericks Enter date 110216472913.53

For Yosemite Enter date 1020133015

Then install.

Thank you for the info. But I already re-downloaded newer versions of the installers and those worked. Thanks