I am following the Detailed Instructions for the exercise. After I click to create the REST integration (step 6):

• I get a popup saying

“http://localhost:9080/prweb says

Generation process has been canceled and all created records have been removed”

• I dismiss the popup
• In the generation summary I see details
  “Canceling rule generation, Error evaluating rules using sample JSON stream

Json Structure :-

{
        "majorDimension": "ROWS",
        "range": "Sheet1!A1:D5",
        "values": [
          [
            "Item",
            "Cost",
            "Stocked",
            "Ship Date"
          ],
          [
            "Wheel",
            "$20.50",
            "4",
            "3/1/2016"
          ],
          [
            "Door",
            "$15",
            "2",
            "3/15/2016"
          ],
          [
            "Engine",
            "$100",
            "1",
            "3/20/2016"
          ],
          [
            "Totals",
            "=SUM(B2:B4)",
            "=SUM(C2:C4)",
            "=MAX(D2:D4)"
          ]
        ]
      }