Calculation group issue PBIRS

Hi NiklasR ,

Calculation groups are a powerful feature introduced in recent updates, but they rely on a model capability (composite models with mixed storage modes) that PBIRS does not yet support.

Once you add a calculation group, it implicitly switches your model to a composite one (since calculation groups require Import mode), which makes it incompatible with the current PBIRS engine even though the UI allows you to add them without any warning. This leads to the very problem you experienced: the file becomes unreadable in PBIRS and Power BI Desktop RS, effectively locking you out of your own report.

Ideally, the UI should restrict or at least warn users when they attempt to add features like calculation groups in a DirectQuery-only model targeted for PBIRS, but as of now, this safeguard doesn't exist. Until Microsoft addresses this gap, the best workaround is to either avoid using calculation groups in PBIRS-bound reports or maintain version-controlled backups of your .pbix files before enabling new features.

This way, you can recover quickly without losing significant development work. You're not alone in this hopefully this gets addressed in a future update with either support for composite models in PBIRS or proper user guidance.