I had signature check issues when installing sierra using a bootable usb device.
The problem was that the bootable usb device I created had one file badly copied. The solution was just to copy this file correctly again and everything works!
- recheck your bootable usb device on your other computer where you kept the sierra installer, by typing in a terminal window:
diff /Applications/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg /Volumes/Install\ macOS\ Sierra/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg
- if files are different, copy the file again by typing:
sudo cp /Applications/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg /Volumes/Install\ macOS\ Sierra/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg
- now you can restart all your install from the bootable usb device. The signature problem should not appear again!
For those who want details, here are all the steps for a clean install:
First be careful, the new macOS versions erase the installer once installed.
=> Copy the installer somewhere else than Applications before launching the install!
Steps:
1.Download Sierra from the Purshase tab in the Apple Store. Quit the installer. Copy the installer somewhere else.
2. Create a bootable usb device
- Format the usb device (needs to be at least 8Go) with a GUID partition
- then, type in a terminal window:
sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/SierraInstaller --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction &&say Done
=> your bootable key is set.
3. Formatting your mac hard-drive:
- Before your format your hard-drive, make sure that you have copied/backup it on another device! and especially that you have copied the sierra installer on another accessible computer in case installation fails.
- start your mac when pressing cmd R or cmd alt R
- go the disk utility
- choose your hard-drive and erase
4. Installation:
- shut down your mac.
- insert your bootable usb device
- start your mac and concurrently press alt to be able to boot on the usb device
- in the utility menu open the terminal
- to check the date, type: date
- if not up to date, change it to the day when you downloaded sierra with the following format (month day hour minutes year), type: date MMDDhhmmYY
- quit the terminal
- choose sierra installation
=> if the signature problem still appears:
- shut down everything
- recheck your bootable usb device on your other computer where you kept the sierra installer, by typing in a terminal window:
diff /Applications/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg /Volumes/Install\ macOS\ Sierra/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg
- if files are different, copy the file again by typing:
sudo cp /Applications/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg /Volumes/Install\ macOS\ Sierra/Install\ macOS\ Sierra.app/Contents/SharedSupport/InstallESD.dmg
- now you can restart all the steps detailed in 4. Installation. The signature problem should not appear again!
