Our team identified an update to HubSpot's OAuth flow that had modified the process to prefer elliptic-curve encryption.
After altering our security settings, the authorization process for HubSpot integrations was restored, and authorizing new or existing HubSpot integrations is again functioning as expected.
Posted Dec 20, 2017 - 16:48 EST
Investigating
At present, the authorization of new HubSpot integrations and the re-authorization of existing HubSpot integrations is leading to errors. Our team is actively investigating the cause.
On-going replication is NOT impacted by this behavior, and users should refrain from re-authorizing existing connections while our team works to resolve this issue.