REST API error on OAuth token refresh

FWIW, I was also running into this issue.   Best I can tell you’ll also hit this error if you issue if you request more than one refresh token for your oauth client.   Each successive refreshToken appears to revoke the prior token.  

I also encountered the same problem, I wonder how you solved it.Could you help me?
The error I received was bad request.
Does the user in the post request need base64 encryption?
There is no redirect\_uri in this request, is it not necessary?

curl -X POST -H "Content-Type:application/x-www-form-urlencoded" \ --user {client-id}:{client-secret} \ --data 'grant\_type=refresh\_token&refresh\_token={refresh-token}' \ https://zoom.us/oauth/token

Hi Sam, 

What error are you receiving when using the curl command?