How to solve error: "Clock skew detected"?
One of the reason may be improper date/time of your PC.
In Ubuntu PC to check the date and time using:
date
Example, One of the ways to update date and time is:
date -s "23 MAR 2017 17:06:00"
Simply go to the directory where the troubling file is, type touch *
without quotes in the console, and you should be good.