OS-X Install – “application can’t be verified” error

During OS-X Install (El Capitan or OTHER)

“This copy of the Install OS X El Capitan application can’t be verified. It may have been corrupted or tampered with during downloading”.

Open Terminal (in installer):

 

1
date MMDDHHmmYY

Where MMDDHHmmYY =

MM - 2 digit month  01 - 12
DD - 2 digit date   01 - 31
HH - 2 digit hour   01 - 24
mm - 2 digit minute 01 - 59
YY - 2 digit year   > 15

The DATE should be about 1 month after your download date of the image files – NOT the current date.