invalid_grant trying to get OAuth token from Google
google-api
Solution
I ran into this problem when I didn't explicitly request "offline" access when sending the user to the OAuth "Do you want to give this app permission to touch your stuff?" page.
Make sure you specify access_type=offline in your request.
Details here: https://developers.google.com/accounts/docs/OAuth2WebServer#offline
(Also: I think Google added this restriction in late 2011. If you have old tokens from before then, you'll need to send your users to the permission page to authorize offline use.)
Problem
I keep getting an `invalid_grant` error on trying to get an OAuth token from Google to connect to their contacts API. All the information is correct and I have triple-checked this so I'm kind of stumped. Does anyone know what may be causing this issue? I have tried setting up a different client ID for it but I get the same result. I have tried connecting many different ways including trying the force authentication, but still the same result.