verify code fails, error output shows a library that it isnt using

The problem is that the IniFile library unnecessarily uses Ethernet.h.

Do this:

  • File > Examples > IniFile > IniFileExample
  • Sketch > Show Sketch Folder
  • Navigate up two folder levels.
  • Open the src folder.
  • Open the file IniFile.h in a text editor.
  • Change line 11 from:
#include "Ethernet.h"

to:

#include "IPAddress.h"
  • Save the file.

I have submitted a pull request to the library author to make this change upstream: