When you view the home page of a Microsoft Windows SharePoint Services site, you may receive one of the following error messages:
Web Part Error: Cannot deserialize (convert an XML stream back into an object) the Web Part on the server.
Web Part Error: One of the properties of the Web Part has an incorrect format. Windows SharePoint Services cannot deserialize the Web Part. Check the format of the properties and try again.
This issue may occur when permissions that Windows SharePoint Services configured on the Windows Temp directory were unintentionally reset , possibly when you upgraded your operating system.
To resolve this issue, make sure that the following permissions are configured correctly:
Windows directory %WinDir%\Temp Administrators - Full Control SYSTEM - Full Control STS_WPG - Read, Write Network Service (for a domain controller only) - Read, Write
%WinDir%\system32\logfiles STS Administrators - Full Control SYSTEM - Full Control STS_WPG - Read, Write Network Service (for a domain controller only) - Read, Write
For a detailed explanation of the minimum file permission settings that must be in place for Microsoft Windows SharePoint Services to perform as designed, view the Files and Permissions topic in the Windows SharePoint Services Administrator's Guide.
For information about how to obtain the Windows SharePoint Services Administrator's Guide, visit the following Microsoft Web site: