With the release of Windows 10, the Windows Update log changed from a text file to a binary file. A new PowerShell cmdlet, Get-WindowsUpdateLog, was added to format the binary file, generating the equivalent text file that many of you were used to. But there was one challenge: The formatting process required access to Windows symbols. As long as the corresponding symbols were available on the Microsoft symbol server (typically used by developers to debug Windows) and you were able to reach the symbol server (on the internet, potentially via a proxy), the formatting would work fine.
But sometimes the formatting didn’t work fine, typically because the symbols weren’t available. That was usually a temporary situation, waiting for the symbols to be uploaded to the server and indexed, but it seems it would always happen when people had a need to format the log.
With Windows 10 1709 (including in the current Insider Preview builds), the formatting process has changed. You still need to use the Get-WindowsUpdateLog cmdlet to format it, but it no longer needs access to the symbols to do that formatting. Notice this screenshot:
Even though the computer has no network connection at all (see the icon at the bottom right), the Get-WindowsUpdateLog worked successfully. And more importantly, we end up with a usable log file: