Microsoft Entra ID shows this error when it receives an authorisation request that it treats as a new admin-consent request. By default, ATS sends prompt=consent in its authorisation URL, which forces this screen even after consent has already been granted tenant-wide.
To resolve this, go to the plugin configuration, locate the Force re-consent option and set it to No, then click and try the button again.
This error appears after you have successfully authorised the application in the popup window but Akeeba Ticket System cannot exchange the authorisation code for an access and refresh token. An HTTP status of 0 means that the HTTP request from your web server to Microsoft’s token endpoint (https://login.microsoftonline.com/) failed completely at the network level.
Common causes:
Your hosting provider’s firewall blocks outbound HTTPS connections to login.microsoftonline.com. Contact your host and ask them to allow outbound HTTPS (port 443) to that domain.
Your server requires an outbound HTTP/HTTPS proxy. If so, configure the proxy in your Joomla! Global Configuration under Server.
An SSL certificate verification error. This is less common since Microsoft uses well-known certificate authorities.
To diagnose connectivity from your server, ask your host to run curl -I https://login.microsoftonline.com/common/oauth2/v2.0/token from your server and report the result.