Hi,
We are developers of a small tool for AdWords.
Recently, we have started seeing "invalid grant" error for many of the AdWords accounts that were previously accessible. I have gone through the list of possible
reasons for refresh token expiry.
The possible reasons we could of think of are
(a) exceeding a certain number of token requests (which I presume mean, the number of API calls)
(b) exceeded total number of refresh tokens we can have
We are not sure about the reason for this behavior. We would like the AdWords API specialists to take a look at our developer token and suggest a possible solution. Please let me know how I can reach you.
Thank you,
Regards,
--shashi