[SOLVED] Board mkrzero (platform samd, package arduino) is unknown

Thanks pert, your suggestion is spot on!

The sketch location is:
C:\Users\USER\Documents\ArduinoData\packages\arduino\hardware\samd\1.6.15\libraries\SPI\examples\BarometricPressureSensor

and the SAMD packages are located here:
C:\Users\USER\Documents\ArduinoData\packages\arduino\hardware\samd

Package deleted, reinstalled and the error has gone.

Now I just need to fix my code to work with the MKRzero...