ERROR: Calendar Visual by MAQ Software showing error message

Hi!!  You’re likely running into a known compatibility issue between the MAQ Calendar visual and the February 2026 version of Power BI Desktop.

The stack trace (Javascript: TypeError at SandboxDelegate.persistProperties) usually indicates the custom visual is failing inside the Power BI sandbox during rendering, not that there’s something wrong with your data model. This commonly happens when Power BI updates WebView2 or the visual sandbox and the custom visual hasn’t been updated to match.

In most cases, the fix is to update or reinstall the MAQ visual from AppSource. If the latest version is already installed and the issue persists, it’s very likely a visual-side bug that needs to be addressed by the MAQ developers.

As a quick sanity check, you can also try placing only Start Date, End Date, and Subject into a fresh MAQ visual. If it still fails, that further confirms it’s not your data but the visual compatibility.

Hope that help! 

best regards!

Thank you, I am having the same issue since yesterday. Let me add more info:

* The visual is updated to the latest build

* The sample pbix that the provider (MAQ Software) have on the Marketplace have the same issue --> So no data issue applies

* I tried with two versions of PBI Desktop (Portal app and MSI version)
* More colleagues are having the same issue with different pbix and different machines.

Since this visual is PBI certified and this change comes from Microsoft, Microsoft should contact MAQ Software to solve this issue ASAP.

Thanks