I have the same problem as @khandakershahi — just noticed it today, and hope it hasn’t been down long as my portfolio doesn’t link to anything now :/
Ditto.
Oddly enough, my short code displays a calendar when only the Calendar ID is entered, but it is blank and will only navigate backward. Once I add the API key, then I get the “Error calling GET” issue.
FYI: The screenshots in the documentation are outdated version of Google Cal. And the only Calendar ID lists my email address.
