I created a new project directory then copied everything across to it from the win 10 user directory.
I then altered the path in preferences, to point to the new directory.
Compilation was fine. I can only assume that I messed up in some way originally by downloading the zip, then later using the library manager, after reading bperrybap note about naming due to git and the problems it caused.
Yeah, don't install using a zip file if the IDE library manager can directly install it.
While installing from a zip file can be done in 1.x IDE I'm sure how zip file installation is handled in 2.x,
With 1.x it often has issues given the way github creates its zip images and the way the IDE handles zip files unless you do some manual correction after the zip install.
I recommend using the IDE library manager capability that automatically installs it for you without using a zip file whenever possible.
It is easier and faster as well.