Using LCD Displays with Arduino
In the case of that library it is actually buried in the .h and .cpp files themselves. Version 1.1 is wat I found in those files. I have never used the library you point out, but the one that was originally used for the video Bill produced. That library has been relocated to GitHub at: New-LiquidCrystal Library
Thank you very much codecage. I cleared my library of existing liquidCrystalI2c libraries and went to GitHub downloaded the zip file, and lo and behold it worked. The LCD_liquidCrystal_demo 2018 now verifies
I have reviewed the original video "Using LCD Displays with Arduino" and in it Bill does say to use the NewLiquidCrystal library for I2C from github.com If I had done this in the first place I would not have had all this trouble. I do not know where the LiquidCrystal library that I had installed came from but it worked on other projects so I assumed it to be ok. I have an existing stop watch that uses the library it is fine as the program does not contain that "POSITIVE" command.
I was determined to succeed after devoting so much time to it, but I still do not know exactly what the "POSITIVE" command does. The same command also appears in the Temperature & Humidity Gauge sketch.
If I remember correctly it controls whether the back light is on or not.