Unknown error when you check out from or publish to a document library

Applies To: Office SharePoint Server 2007

This Office product will reach end of support on October 10, 2017. To stay supported, you will need to upgrade. For more information, see , Resources to help you upgrade your Office 2007 servers and clients.


Topic Last Modified: 2016-11-14

You receive an error condition in Microsoft Office SharePoint Server 2007 when you try to check out or publish from a document library in Office SharePoint Server 2007.

If you installed Office SharePoint Server 2007 Standard Edition on a stand-alone server computer by using the Complete option, certain functions in the Shared Documents library — for example, check in, check out, or publish — produce the following error:

Error=Unable to validate data. at System.Web.Configuration.MachineKeySection.GetDecodedData(Byte[] buf, Byte[] modifier, Int32 start, Int32 length, Int32& dataLength) at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)


The error is caused by an incorrect installation and configuration of Office SharePoint Server 2007. This error, reported in system diagnostics during application operations, may indicate a work-around that instructs the administrator to change machine key values in the Office SharePoint Server 2007 farm to resolve the issue. Microsoft does not require or recommend that system administrators edit machine key values. The underlying cause of the error is a configuration issue that may have occurred during or following the initial Office SharePoint Server 2007 farm installation.


Test and verify your Office SharePoint Server 2007 Standard Edition farm installation method and isolate possible errors in application code or in post-installation configuration. To do this, create a new Office SharePoint Server 2007 Standard Edition baseline Virtual Machine by using the procedures in the following article in the Microsoft Knowledge Base: Unknown Error in Microsoft Office SharePoint Server 2007 (http://go.microsoft.com/fwlink/?LinkId=116157\&clcid=0x40).