re installing OSX problems

"You’re hitting an expired certificate issue! Here’s more on it If you've got an old macOS install image, it will probably stop working today

Apple has been doing this for years! You mostly on hit this issue on systems which can’t support newer OS’s. As an example I had to re-install Lion for someone as they just didn’t want anything newer (90 year old lady) who just didn’t want to relearn how to do things or have the will to update her apps.

The issue you face with the newer macOS’s is Apple didn’t update the certificate which is why this has become more of an issue as of late. Here’s the updated installers:

How to upgrade to OS X El CapitanHow to upgrade to macOS SierraHow to upgrade to macOS High SierraHow to upgrade to macOS Mojave

In all of these just jump down to Step 4 to get to the URL link for the OS image.

Apple did not alter the older images in their downloads. Some Internet recovery images likewise have not been updated.

OK, What about the older ones!

Not to fear! You can still install the OS. The trick is back dating the systems clock! Alter the Date & Time setting from auto set to manual and then alter the date to a year that is within the given OS’s release window. Now your older OS installer thumb drives will work! Just remember to re-set the Date back to the correct year and set it back to auto."

You might have install images that Apple considers outdated. Try turning off Wifi and take Mac’s clocks backwards in the past. You can either do that from a working external disk or you’ll have to do it from the terminal using the Set Date command, you can easily find the correct syntax with a google search. Do not let Wifi working or it will adjust the time again when the installer calls Apple servers.

I'm getting this same error from trying to reinstall over the net. I tried the clock thing and had to do it through the terminal but I'm at a loss. Any ideas?

@dan I’m basically in the same boat as everyone here (wiped 2011-12 MacBook Pro, trying to reinstall OS) and I’m to the point where I am rebooting and entering disk utility. I have an OSX LION install file on a thumb drive, but I cannot figure out the next step. How do you access the file on the thumb drive? I go into disk utility and the only option I see there is to restore and create a new disk image. I’ve done that, but now I’m at a roadblock