pert:
Apparently the FirmwareUpdater sketch you're using has this code at line 19:#include <strings.h>However, the official WiFi101 library's FirmwareUpdater (File > Examples > WiFi101) sketch does not contain that line. Where did you get your FirmwareUpdater sketch?
this is in Uno WiFi Rev 2 section.
you get this error if you try to compile the WiFi101 FirmwareUpdater sketch for Uno WiFi Rev2
I don't know right now the procedure for the Uno WiFi Rev 2