Unable to login to purview once Classic interface retired

Hello jcrowland,

From your description, looks like you are trying to sign in to the classic governance portal. Are you trying to access any of the governance solutions or other solutions, like DLP, ediscovery, etc.,?

If you are trying to login to governance portal, try to launch from the azure portal directly from the purview resource. Refer to the second bulletin under: https://learn.microsoft.com/en-us/purview/legacy/use-microsoft-purview-governance-portal#launch-microsoft-purview-account 

Have you considered upgrading to the new portal experience to make it easier? Refer to the documentation here that covers in detail on how to do this: Learn about data governance in the Microsoft Purview portal | Microsoft Learn

For other solutions, try launching the new portal directly: https://purview.microsoft.com/ 

There is no documentation that I could find relevant to this particular issue. However, here are some references covering the known issues and roadmap. 

Known Issues in Microsoft Purview Data Governance | Microsoft Learn

What's new in Microsoft Purview | Microsoft Learn

MS-Purview-Data-Governance-Roadmap-detailed.pdf

Microsoft 365 Roadmap | Microsoft 365 

Hope this helps!

Regards,

PI

Please mark as solution, if you find the answer helpful. This will assist others in the community who encounter a similar issue, enabling them to quickly find the solution and benefit from the guidance provided.