When attempting to update .NET Reflector's Visual Studio extension, the installation can fail with a message:

The certificate for a digital signature in this extension is not valid.

This will affect people trying to use check for updates on XP / Windows Server 2003 to upgrade the Visual Studio extension in Visual Studio 2010

This is a Microsoft bug and is detailed here: http://support.microsoft.com/kb/2581019

The issue occurs because Windows XP and Windows Server 2003 handle the Certificate Revocation Lists (CRL) differently than other operating systems.

When Extension Manager handles the Certificate Revocation Lists (CRL), Extension Manager uses the same method for all operating systems. However, Windows XP and Windows Server 2003 handle the Certificate Revocation Lists (CRL) differently than other operating systems. Therefore, issue 2 occurs.

The Workaround:

To work around this bug:

1. Go to Visual Studio > Tools > Extension Manager and uninstall the old .NET reflector package.
2. Download the new installer from the Reflector website
3. Run the installer.

Let us know if you still have any trouble with this bug, and we'll investigate further.