Other Customers using Winc 1500 WiFi shields are having the similar issues. The problem seems to come from the programms of the WiFi101 library itself. Since I like monologues, I thought I would post the solution that worked for me:
(credits to franklin97355 on the Adafruit forums)
Unzip the file and put it into your Arduino library folder. If you are following the steps of the guide, you should be able to carry on without any troubles.