Invalid Token! (invalid_grant) when trying to renew a token on our app

Our app, Delenta (Client ID REDACTED), is having issues refreshing a customer’s token.

We have done many tests ourselves via our own personal keys and can confirm our code works, however, when we try and run this (via Postman):{REDACTED}

We get:

“reason”: “Invalid Token!”,
“error”: “invalid_grant”

We have spoken to the customer many times and they have not used their account elsewhere on our app from what we can tell as such this refresh token should not be disabled.

We have checked this is the right and current refresh key, our own code works well for our own keys but not this one, for example:{REDACTED}

Any insight as to why this isn’t working?

Hi @Delenta ,

Can you please submit a support ticket with this request?


  • production client id
  • user email(s)
  • full request/responses
  • anything else you think would be helpful for us to help debug!


Yeah, we already did, they told us to post here

We’ve been seeing the same error on our production systems, intermittently. We have many customers creating thousands of Zoom meetings, but rarely (several times a month at our scale), when we fetch a new refresh token, we get this error with status code 400:

“reason”: “Invalid Token!”,
“error”: “invalid_grant”

This user reported a similar issue but the error was “invalid_request” and the status code was 401: ZOOM API refresh token not working {"reason":"Invalid Token!","error":"invalid_request"}

It seems similar to this error, which is basically a race condition: Intermittent 400 error when refreshing token "Save Access token into Database error"

Can your engineers provide insight into the 400 invalid_grant Invalid Token! error? It seems to be a bug in Zoom’s API.

I suspect that this is just another race condition (ie we are using the same refresh token to fetch a new refresh token twice, very quickly). But it would be nice to know what the error means for sure.

When this happens, the next request typically goes through without problem, so there is definitely nothing wrong with the credentials.

Facing the same issue. The refresh token seems to work once - and then the subsequent requests throw this error.

"{\"reason\":\"Invalid Token!\",\"error\":\"invalid_grant\"}"

I am experiencing the same issue, did you figure out a way around this?

@zac1 and @dev_kd ,

Can you share if you are still seeing this behavior on your end?

April 21

@zac1 and @dev_kd ,

Can you share if you are still seeing this behavior on your

Yes we are seeing that behavior in our application. The refresh token is not able to get us a new access token.
Although after a while this is automatically resolved where the refresh token works as expected.



Thank you for confirming. Can you submit a support ticket for this? This way we can take a closer look at our logs and diagnose what may be happening. You can submit a request with our support here:

Be sure to include a link to this thread along with the following details:

Complete Refresh Token API request :

Headers :

Error Message returned :

Time/Date of Request:

OAuth User Details :

AccountID :

Refresh Token :

Access Token :

ExpiresAt :


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