El Capitan Cannot Be Verified

  • DVD DL, Mac OS X 10.11 El Capitan Full OS Install Reinstall Recovery Upgrade. Latest certificate (expires ). Please CHECK twice if your Mac model is compatible with this macOS!! If you are not 100% sure please check the pics or message me your mac model and year and I can tell for sure if would work or not!
  • Listed by Elation Real Estate, Piper, Gina. 2855 El Capitan Dr, Pleasanton, CA 94566 (MLS# 40962876) is a Single Family property with 2 bedrooms and 2 full bathrooms. 2855 El Capitan Dr is currently listed for $925,000 and was received on August 23, 2021.

Now, I've have been trying for a week and a half to get either 10.10 or 10.11 to install and I receive the same message from both: 'This copy of the Install OS X Yosemite (or El Capitan) application can't be verified. It may have been corrupted or tampered with during downloading. Cancel out to the installation (If you are still on your bootable image of El Captain). Go to Utilities - Terminal. If your date is correct, then proceed to the next section below. If it’s not correct, continue with these steps. Set the current date and time.

Cannot
  • I am trying to upgrade an older iMac (2008) from OS 10.6.8 to El Capitan for a disabled client who really needs to use a Mac instead of a PC!
  • EveryMac says it can handle El Capitan if I upgrade RAM. It has 4GB now.
  • I have an Installer file from my own Mac (always keep them when I upgrade). I made a bootable flash installer that mounts and seems to have the proper files, but it won't show up on either Mac on restart holding option key; nor in the Startup Disk list. So, I figured writing to the flash drive must have failed.
  • I partitioned an external hard drive and redid this:

    'sudo /Applications/Install OS X El Capitan.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install OS X El Capitan.app'

  • It seems to work (again) in Finder AND it shows up as a boot option on restart (holding option key), but when I select Install OS X I get an error that the installer cannot be verified. I can't get it to work.
  • So, I figured my installer must have gone bad, even though I successfully upgraded my own Mac with it, and have since upgraded mine to Sierra.
  • Using the App Store I can get to El Capitan, but it will not allow me to download it on my Mac because the system is too new, and I don't want to download it to the old Mac because I want to use an external drive to do a clean install; not an upgrade on the old one.
  • Any advice?

IMAC (RETINA 5K, 27-INCH, LATE 2015), macOS Sierra (10.12.3)

El Capitan Cannot Be Verified Full

Posted on Feb 28, 2017 9:53 PM