Who is this article for?

Users working with the desktop application.

No special access or permissions are required.

The Windows 11 August 2026 cumulative update (KB5120708) for .NET Framework 3.5 and 4.8.1 has introduced an issue that prevents printing from functioning in Aura.

Issue

When attempting to print from Aura after installing KB5120708, you may encounter one or more of the following error messages:

Error 1: XamlParseException

EXCEPTION: XamlParseException

message: 'Failed to create a 'ImageSource' from the text '/Resources/7cc06dcb-4e75-4529-bbbb-568180f6e7b3.png'.' Line number '1' and line position '367'.

Error 2: FileFormatException – External URI Reference

EXCEPTION: FileFormatException

message: The URI references a resource outside the current XPS package. External URIs (http, https, file, UNC, cross-package) are not permitted when loading XPS content.

Error 3: FileFormatException – Font File Format

EXCEPTION: FileFormatException

message: 'file:///C:/WINDOWS/FONTS/CALIBRI.TTF' file does not conform to the expected file format specification.

These will prevent you from printing from the data grid in Aura. 

Workaround

Microsoft is investigating this issue.

Important

Ideagen does not recommend removing or uninstalling KB5120708, as it is a security update. Removing security updates exposes your system to known vulnerabilities and is not a supportable long-term solution.

Microsoft have suggested a workaround that may allow successful printing.  Full details (including relevant warnings) are provided in this knowledgebase article.

In order to implement Microsoft's workaround, add the following xml to the client file vision.exe.config, 

  <runtime>
   <AppContextSwitchOverrides value="Switch.MS.Internal.TtfDelta.DisableCmapAndSbitOverflowProtection=true;Switch.System.Windows.DisableXpsPackageBoundaryRestriction=true"/>
 </runtime>

To do this in ClickOnce:

• Open App Manager, and connect to the correct intance
• Go to the Client tab
• Copy the xml above, and paste to the line above </configuration>:
  
  
   
• Click save 
• Then, the next time a user opens their desktop application the changed file should be copied to their machine.  After the second launch the change will take effect