Advisory: Reporting Issues Following Recent Windows Updates

We would like to inform you about a technical issue caused by recent Windows operating system updates. This situation may impact report generation, printing, and document export in some of our older applications. Our newer software solutions remain unaffected by this issue.

What Happened

In August and September, Microsoft rolled out regular security updates for the .NET Framework (versions 3.5, 4.8, and 4.8.1). Regrettably, these system updates introduced a regression bug that disrupts report rendering based on XPS technology.

This issue first appeared in the August updates (August 11, 2026) and continues to persist in the subsequent September updates (September 8, 2026).

The specific Knowledge Base (KB) numbers vary depending on your Windows version:

  • Windows 11:
    • August 2026: KB5120708 (or KB5120710 depending on OS build)
    • September 2026: KB5126052
  • Windows 10:
    • August 2026: KB5120709 or KB5120701
    • September 2026: KB5126048 (or the corresponding .NET cumulative package for your build)

When these updates are present on a machine, older applications will typically encounter an error whenever a report is opened or printed.

Nature of the Issue

The error originates inside Windows system libraries during the font processing of common typefaces (such as Calibri or Cambria) while preparing documents for printing or export. The Microsoft development team has analyzed the defect and prepared an internal code fix, but this has not yet been rolled out through public Windows Update channels.

Recommendations for Affected Users

  • If your IT department has not deployed these updates yet: We recommend pausing or postponing the deployment of the August and September .NET Framework cumulative updates on workstations running affected applications.
  • If the updates are already installed and reports fail to open: We suggest contacting your internal IT team to request a temporary removal of the listed updates (or rolling back to an earlier system restore point).

Next Steps

We are closely monitoring the situation. In the first instance, we are waiting for Microsoft to officially release an updated servicing patch. Once that update becomes available, we will thoroughly test its behavior and compatibility with our applications to evaluate the outcome and determine any subsequent steps required to restore full stability.

We will keep you informed of any further developments.

If you have questions regarding your application version or require assistance, please feel free to reach out to our technical support team.

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