It can often be difficult getting SAML authentication to work as expected. If you do run into issues, here are some points that you can check prior to submitting a ticket.
Verify the creation of a claim on the IdP side
It is important to ensure that a claim has been created on the IdP (identity provider) that you have chosen to use. A claim is information that an identity provider states about a user inside the "token" or unique identifier that they issue for that user. Your Posit configuration uses this claim as a point of reference, and your claim is used to retrieve information from your user identity store.
Make sure the metadata URL is correct
It is possible for your metadata URL to change from the IdP side if there are configuration changes made to your SAML infrastructure. You can ensure that your metadata URL is correct by using curl or downloading the metadata URL by pasting it into your web browser. From there, you should be able to download the metadata file and analyze its contents making sure that the details in the metadata XML file are correct.
Ensure that you have configured your Posit Infrastructure correctly
You can refer to our documentation on configuring Posit Teams for SAML here:
Posit Workbench
https://docs.posit.co/ide/server-pro/authenticating_users/saml_sso.html
Posit Connect
https://docs.posit.co/connect/admin/authentication/
Confirm that the SSL certificate on the IdP side is valid
SAML authentication will fail if the SSL certificate on the IdP side is expired or invalid.
Generate a HAR file
If the above is all correct, then your SAML configuration should work! However, if it doesn't, please generate a HAR file while performing a login that isn't working, which will allow us to see why the assertion is either not coming back from your IdP or coming back with the incorrect details. Instructions for how to generate a HAR file can be found here:
https://support.posit.co/hc/en-us/articles/4413166624279-Capturing-a-HAR-File
Support Ticket
If you still have issues after completing the above, you can always lodge a support ticket, where our group of friendly and knowledgeable staff can assist with any issues that you may be having. You can submit a ticket here:
https://support.rstudio.com/hc/en-us/requests/new