April 2026

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In recent days we have seen several support cases where Kerberos authentication in SharePoint suddenly starts to fail. In the SharePoint ULS logs you may see errors such as: System.ServiceModel.Security.SecurityNegotiationException: A call to SSPI failed System.Security.Authentication.AuthenticationException: A call to SSPI failed System.ComponentModel.Win32Exception: The encryption type requested is not supported by the KDC Cause Starting with […]

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Important: If your current farm patch level is September 2025 CU, execute the following PowerShell script to correct the folder permissions on the relevant folders otherwise installing the SharePoint fixes will fail: Fix-SeptemberCU-Permission-Problem.ps1 Alternatively you can also remove the NT Authority\system account from WSS_WPG and IIS_IUSRS local security groups of the SharePoint machines. For more […]

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Important: If your current farm patch level is September 2025 CU, execute the following PowerShell script to correct the folder permissions on the relevant folders otherwise installing the SharePoint fixes will fail: Fix-SeptemberCU-Permission-Problem.ps1 Alternatively you can also remove the NT Authority\system account from WSS_WPG and IIS_IUSRS local security groups of the SharePoint machines. For more […]

- - 0 Comments

Important: If your current farm patch level is September 2025 CU, execute the following PowerShell script to correct the folder permissions on the relevant folders otherwise installing the SharePoint fixes will fail: Fix-SeptemberCU-Permission-Problem.ps1 Alternatively you can also remove the NT Authority\system account from WSS_WPG and IIS_IUSRS local security groups of the SharePoint machines. For more […]

- - 13 Comments

Important: If your current farm patch level is September 2025 CU, execute the following PowerShell script to correct the folder permissions on the relevant folders otherwise installing the SharePoint fixes will fail: Fix-SeptemberCU-Permission-Problem.ps1 Alternatively you can also remove the NT Authority\system account from WSS_WPG and IIS_IUSRS local security groups of the SharePoint machines. For more […]