Just started playing with Arduino (nano) on (1.8.5) (on Win 7) after a few years break
I tried to install a (LiquidCrystal_I2c) Library by creating a directory in 'Program Files\Arduino\Libraries' and then copying the downloaded files. Library did not appear when I did 'Sketch|Include Library' in IDE.
I then noticed the 'Add Zip Library' (which must be new I guess) but same problem.
A search on the machine reveals that it has installed the library in \Users\user\MyDocuments\Arduino\Libraries.
How can 'Add Zip Library' and Sketch|Include Library be using different?
Joe_Jefferies:
I tried to install a (LiquidCrystal_I2c) Library
Please post a link to where you downloaded the library from. Use the chain links icon on the toolbar to make the link clickable.
Joe_Jefferies:
by creating a directory in 'Program Files\Arduino\Libraries' and then copying the downloaded files.
That's a bad idea. Anything you install to that location will be lost when you update to a new version of the Arduino IDE. You should always install libraries to the sketchbook folder (which you can see/set in File > Preferences > Sketchbook location).
Joe_Jefferies:
A search on the machine reveals that it has installed the library in \Users\user\MyDocuments\Arduino\Libraries.
\Users\user\MyDocuments\Arduino is your sketchbook folder.
Joe_Jefferies:
How can 'Add Zip Library' and Sketch|Include Library be using different?
That question doesn't make sense. I guess you meant to ask: "Why does the library installed via Add Zip Library not show under Sketch| Include Library?" To answer that question, I'll need the link to the library you downloaded.
I could probably figure out what went wrong if I had more details of what you did. Are the steps I recommended above different from what you did originally? The .zip download link in those steps is the same as clicking Clone or download > Download ZIP on the home page of the library's GitHub repository.