Unable to connect to the server.
Could not establish trust relationship for the SSL/TLS secure channel with authority.
Cannot connect to Dundas webpart in Sharepoint due to the SSL connection not getting established between Dundas and Sharepoint.
This error means that the certificate is not trusted for the connection between Dundas and Sharepoint and is related to the root certificate not being installed on the SharePoint machine and the Sharepoint Central Administration. Even if the certificate was purchased/signed, it still needs to be installed in the trusted store.
1) Get the root certificate related to the Dundas website.
2) Install the root certificate on the SharePoint machine in the trusted certificate store.
3) The root certificate also needs to be installed through SharePoint Central Administration. Under the Security->General Security->Manage Trust section select New, give it an appropriate name and then use add the certificate.
Now try to connect the web part. It should say “Connected” under Connection Status.