Remote MCP server returns -32603 on all tools/call with Service Principal

Hi all_eyes_on_you,

Thank you for reaching out to Microsoft Fabric Community.

Thank you for the response, this does not look like service principal configuration issue, since authentication, initialize, tools/list and the Power BI REST API are all working successfully with the same token.

• As multiple MCP tools are returning the same error, this look like service-side issue or regression with the Remote Power BI MCP server rather than a problem in your application.
• If this was working previously and no changes were made on your side, I recommend opening a Microsoft Fabric Support ticket so the product team can investigate the backend behaviour.

Create a Fabric and Power BI Support Ticket - Power BI | Microsoft Learn

Thanks and regards,

Anjan Kumar Chippa