expire_in returns an expired access token

[nawar]

Suddenly, any authentication using this starter code is returning an access code that is expired. In my case, it's returning a token that is expired at 2017-05-11. The code has been working fine for months, so I'm not sure what's has changed on.

When I try to create make a request, I get the response

{
    "error": {
        "code": "InvalidAuthenticationToken",
        "message": "CompactToken validation failed with reason code: -2147184088.",
        "innerError": {
            "request-id": "6be04d77-3389-4f8b-8c6b-be54f2a436bd",
            "date": "2017-10-16T02:35:55"
        }
    }
}

and when trying to refresh the access token, I get the following error

{
    "error": "invalid_grant",
    "error_description": "AADSTS70000: The user could not be authenticated or the grant is expired. The user must first sign in and if needed grant the client application access to the requested scope.\r\nTrace ID: 1dc8435e-40c1-4db0-9155-a414e73a7500\r\nCorrelation ID: d20c058c-5ffd-433b-9f78-80034f34d8ee\r\nTimestamp: 2017-10-16 00:52:05Z",
    "error_codes": [
        70000
    ],
    "timestamp": "2017-10-16 00:52:05Z",
    "trace_id": "1dc8435e-40c1-4db0-9155-a414e73a7500",
    "correlation_id": "d20c058c-5ffd-433b-9f78-80034f34d8ee"
}

Would love to get some insight on the issue.