[solved] How to Fix macOS Sierra when u reinstall macOS to El CapitanWritten by Alex Thursday, 09 November 2017 11:52
How to fix OS X application can't be verified | OS X El Capitan | macOS Sierra | Yosemite Corrupted or Damaged during Downloading in Easy Steps.
"This copy of the install OS X Yosemite (any OS X) application can't be verified. It may have been corrupted or tampered with during downloading"
Try change system date using Terminal and it will work. Run this command in Terminal (go to Utilities -> Terminal):
Date 0320015315 (month_date_time_year) String of numbers = month 03, date 20, time 0153, and year 15, combined.