Bob

Resolved my issues. After many hours I finally realised this was an error on my behalf. The PHP ltrim function I was using to truncate the refresh_token from the initial callback response was dropping the first character off the refresh_token, in essence providing an invalid refresh_token. Not sure why it was doing this so used str_replace.and it's now working. #Old code $refreshToken = ltrim($refreshToken, "refresh_token:"); #New code $refreshToken = str_replace("refresh_token:", "",$refreshToken);

Did you resolve this issue? I have run into what I believe is the same problem. I get the initial Access Token and Refresh token no issues, however when I attempt to renew the Access Token via the Refresh Token I am also getting, "failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request"