Overview

After applying the June 2026 Microsoft Windows Security Updates (released on June 9, 2026), July 2026 Microsoft Windows Security Updates, and/or August 2026 Microsoft Windows Security Updates, SAS^® 9.4 customers might be unable to start Base SAS^® or connect to a SAS server from SAS^® Enterprise Guide^®.

This issue occurs after installing the following known Microsoft Updates:

• Windows 11 (24H2 / 25H2)
  • KB5094126 - June 2026 cumulative update
  • KB5101650 - July 2026 cumulative update (supersedes/includes KB5094126)
  • KB5121003 - August 2026 cumulative update (supersedes/includes KB5094126 and KB5101650)
    
    
• Windows Server 2019 (1809)
  • KB5094123 - June 2026 cumulative update
  • KB5099538 - July 2026 cumulative update (supersedes/includes KB5094123)
    
  • KB5120238 - August 2026 cumulative update (supersedes/includes KB5094123 and KB5099538)
    
    
• Windows Server 2022 (21H2)
  • KB5094128 - June 2026 cumulative update
  • KB5099540 - July 2026 cumulative update (supersedes/includes KB5094128)
  • KB5120242 - August 2026 cumulative update (supersedes/includes KB5094128 and KB5099540)
    
    
• Windows Server 2025 (24H2)
  • KB5094125 - June 2026 cumulative update
  • KB5099536 - July 2026 cumulative update (supersedes/includes KB5094125)
  • KB5120233 - August 2026 cumulative update (supersedes/includes KB5094125 and KB5099536)

When the issue occurs, launching Base SAS fails during initialization, and SAS Enterprise Guide is unable to connect to Base SAS.

Symptoms

When you start Base SAS, the following errors appear:

ERROR: Invalid physical name for library SASUSER.
NOTE: Unable to initialize the options subsystem.
ERROR: (SASXKINI): PHASE 3 KERNEL INITIALIZATION FAILED.
ERROR: Unable to initialize the SAS kernel.

Cause

When installed, the June 2026 Microsoft Security Updates released on June 9th, 2026 (and/or the July 2026 Microsoft Security Updates released on July 14th, 2026, and August 2026 Microsoft Security Updates released on August 11th, 2026), have been found to affect certain access to the Windows known folder resolution for the ?FOLDERID_Documents location, but only when the logged-on User's Documents folder is redirected to a remote network location.

When SAS attempts to initialize the SASUSER library by using the affected Documents folder path, SAS might be unable to read/write to the location correctly. This prevents the SAS options subsystem and SAS kernel from initializing successfully.

Determine the Documents Folder Path

To determine the current Documents folder path for the affected Windows user account, run the following PowerShell command:

(Get-ItemProperty -Path "HKCU:\software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders" -Name Personal).Personal

This command returns only the Personal value from the Windows User Shell Folders registry key. The Personal value identifies the path that Windows is using for the user's Documents folder.

If the Personal value returns a path to a network or other non-local drive, such as a UNC path, that indicates the Windows user account is affected by this problem.

For example, a returned path similar to the following indicates that the Documents folder is redirected to a network location:

\\network.machine.com\Users\userID\Documents

Workaround

SAS is currently investigating the changes in these Windows Updates with Microsoft and will provide updates when available for additional recommended workarounds or resolution. Until then, the supported steps to get around the problem are to explicitly set the -SASUSER option in the SAS configuration file to use the resolved Documents folder path.

Note: Administrator rights on the machine are required to complete the following workaround steps.

Step 1: Back Up the SAS Configuration File

Make a backup copy of the sasv9.cfg file before making changes.

The default English-language configuration file location is:

C:\Program Files\SASHome\SASFoundation\9.4\nls\en\sasv9.cfg

Step 2: Identify the Documents Folder Path

Run the following PowerShell command:

(Get-ItemProperty -Path "HKCU:\software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders" -Name Personal).Personal

Copy the returned Documents folder path.

Step 3: Update the -SASUSER Option

Open the sasv9.cfg file in a text editor that has administrator privileges.

Locate the -SASUSER option and update it to use the Documents folder path from Step 2, followed by:

\My SAS Files\9.4

Use the following format:

-SASUSER "<Documents folder path>\My SAS Files\9.4"

For example:

-SASUSER "\\network.machine.com\Users\userID\Documents\My SAS Files\9.4"

Note: If multiple SAS users share the same machine and their Documents folders follow a consistent naming convention that includes their Windows user ID, you can use the %USERNAME% environment variable so that each user automatically receives a unique SASUSER location. 

For example:

-SASUSER "\\network.machine.com\Users\%USERNAME%\Documents\My SAS Files\9.4"

When SAS starts, %USERNAME% is replaced with the currently logged-in Windows username. This allows multiple users to share the same SAS installation while maintaining separate SASUSER directories.

Step 4: Save the Configuration File

Save the updated sasv9.cfg file.

Step 5: Restart SAS

Start Base SAS or reconnect from SAS Enterprise Guide.

The SAS session should now initialize successfully.

Additional Notes

• This workaround should be applied for the Windows user account that is affected by the redirected Documents folder path.
• If multiple SAS users are affected, each user's Documents folder path should be verified before updating the -SASUSER value.
• Always back up the original sasv9.cfg file before making changes.
• If the Microsoft Windows updates listed above were not installed, or if the workaround in this article does not resolve the problem, use the additional SASUSER troubleshooting guidance linked in the Workaround section.