When an InfoPath web enabled form tries to access a SharePoint web services (usually for getting user profile information, values from custom list etc.) from a web application using a secured connection (SSL), it may show the following error.
You do not have permissions to access a Web service that provides data required for this form to function correctly.
In the ULS log or Windows Event Viewer in the web front end server you will see the following error.
An operation failed because the following certificate has validation errors:\n\nSubject Name: CN=<some text>, OU=<some text>, O=<some text>, L=<some text>, S=<some text>, C=<some text>\nIssuer Name: CN=<some text>, O="<some text>", C=US\nThumbprint: <some text>\n\nErrors:\n\n The root of the certificate chain is not a trusted root authority..
This is because, when you use SSL certificate for your web application URL, the certificate needs to be imported into SharePoint trusted root certificate store (if you are using NTLM). If you are using claims based authentication, you may need to import the certificate you used for token signing. I have explained how you can in export the certificate and import it into SharePoint trusted root certificate store in this article.