OSX USB Install Troubleshooting April, 2020 Usually occurs when installing a new hard drive. And Unplugging the battery to put it in. Fix: The installer payload failed signature check During USB install of Mac OSX In Utilities, open up the terminal type “date” press enter I should show the system date, which is wrong, type in : date [today’s dat] in this format month(2 digits) day(2 digits) time( 4 digits- military time) year( 2 digits) Here is our example for April 13th, 2020 at 4:12 pm date 0413161220 04 - is the month 13 - is the day 1612 - Is time in military time (4:12pm) 20 - is the year so type in: date 0413161220 then ENTER (With of course the current date and time represented after date)
For making a clean install of OS X Mojave and Sierra. Make sure the install file is its original name and in the Applications folder. Make sure your USB drive is 16g for Mojave and 8g for Sierra Sierra: Connect the USB flash drive to the Mac, then rename the USB drive to “SierraBootInstall” – yes you can pick a different name just be sure to edit the command syntax to reflect that Open “Terminal”, found within /Applications/Utilities/ Place the following command syntax into the Terminal: sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/SierraBootInstall --applicationpath /Applications/Install\ macOS\ Sierra.app --nointeraction &&say Done Mojave: sudo /Applications/Install\ macOS\ Mojave.app/Contents/Resources/createinstallmedia --volume /Volumes/UNTITLED --nointeraction && say Mojave Drive Created