We have been notified that the SSL certificate assigned to our main API endpoint api.smartip.io was getting flagged as REVOKED. Trying to execute API calls from any browser were resulting in error messages with code: SEC _ ERROR _ REVOKED _ CERTIFICATE.
For some unknown reasons the SSL certificate had been revoked without any notification coming from the CA. We quickly fixed the issue, getting a new certificate and the system is now up and running as normal.
Apologies for the inconvenience.