This problem with the libraries is an ongoing mess. Sometimes it works, sometimes it doesn't. When it does not the Arduino IDE does not list the ESP8266 boards. Sometimes it works on one computer and fails on another. Sometimes it fails on both using the Arduino IDE. I also have the Visual Micro installed for Visual Studio 2017 and when the Arduino IDE, fails, I can jump onto Visual Micro and continue working. (MOST of the time). I will post a different problem I encountered last weekend with the libaries becoming corrupted.
After digging on the Internet, I finally found a page that described how to manually install the boards and libraries from GITHUB without using the Arduino IDE Preferences and boards manager.
https://www.esp8266.com/viewtopic.php?f=26&t=12599
For now, that is the solution I am using and it seems to be working OK.