Couldn't complete the connection An error occurred while validating the app authorization.

We are passing the correct client ID, secret, and redirect URL. This app has worked for many customers in the past, but sometime in the last couple of weeks, Hubspot stopped accepting it.
The above error is now being thrown in the OAuth flow, after the user approves my app. What could cause this change?

Ditto for us too. Worked in the past, stopped working. Were you able to find a resolution?

Quick update if it helps anytone: For us, it turns out to be the ‘reports’ scope. Apparently that has been deprecated. Once we removed that from the scope, it worked.

same here.
Nothing changed (scopes, credentials etc) and it just stopped working a couple days ago.
Any idea where to find solution ?

while authenticate with Oauth2 with passing client id and secret key
getting this issue-ouldn’t complete the connection
Authorization failed as the redirect URL ‘https://web5.mclsystems.com/Myappflow/RestApi/oauthCallBack’ doesn’t match the app’s registered redirect URL. Please consult the app developer.
how to resolve it