2018-08 Cumulative Update for Windows Server 2016 (KB4343887) Failing

TL;DR:

Clear your C:\Windows\Temp directory and other Temp directories for good-measure - then it should install updates fine.

Explanation:

As this is an Azure VM, Microsoft's "Basic" support tier is available - granted it took 3 days to arrange a phone-call, but the support staff were able to find a workaround just today.

In the CBS.log file he spotted this line (trimmed and tidied-up by me):

2016-08-16 20:26:50, Error                 CSI    00000006@2016/8/16:20:26:50.808 (F) CMIADAPTER: Inner Error Message from AI HRESULT = 8004402f [Error,Facility=FACILITY_ITF,Code=16431 (0x402f)]
[
[210]"Parsing MOF file: C:\Windows\system32\wbem\NetTCPIP.mof
Error 80 in Function CMofLexer::CMofLexer line 614
C:\Windows\system32\wbem\NetTCPIP.mof (1): error SYNTAX 0X8004402f: Error creating temporary file"
]
[gle=0x80004005]

The important bit being this error:

Error creating temporary file

He instructed me to change the default environment-variables: TEMP and TMP in both System and User definitions to C:\TEMP and to ensure Everyone had Full Access to C:\TEMP.

After rebooting the clogged-up updates installed without any further issues.

After installing those updates fine I then deleted all of the files in the original C:\Windows\Temp directory (which took 5+ minutes, there were a lot of deeply nested files). I then reset the TMP and TEMP environment variables back to C:\Windows\Temp and rebooted.

Two new updates were then ready to install and installation completed without any problems.

So I think the problem was bad data in the Temp directory that prevented the updates from doing anything.

Update in Mid-2017: I had a similar incident on a Windows 10 laptop recently with the same error code. I immediately went to the C:\Windows\Temp directory and saw it had a lot files in it (about 16,000 files and folders), including deeply-nested folders too. After I deleted everything in the directory and rebooted I was able to install the updates again.

I was able to fix this as follows:

I had the same experience with a new Dell server, loaded with Server 2016 with English, Japanese, French, Spanish, and Korean languages pre-installed.

Something went south and the language pack for Korean was not installed. But the OS registry entries in HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\PackageDetect were created and orphaned.

When I tried to install some roles or features the error

The referenced assembly could not be found.

was returned, due to the install looking for those referenced language entries that were not installed.

If you open powershell and run lpksetup, click on uninstall display languages and see which languages are installed. I uninstalled all extra languages, one at a time.

Now you can try the install and when it fails goto c:\windows\logs\cbs. Throw the CBS log into notepad and search for the text error. Look for a line with

error CSI 0000000a (F) HRESULT_FROM_WIN32(ERROR_SXS_ASSEMBLY_MISSING)

the next line with, say

Info CBS Failed to pin deployment while resolving Update:

might have the name of the package that is missing.

If you're lucky, it will have a language code EN, ES, ko-KR, etc...

That's the language package that has been orphaned!

Now the fun part. You can

1. Delete all the entries in the registry, a lot of them!

or

2. Download the language pack or language pack ISO for 2016 server and install the language pack for the offending language using the lpksetup utility and the cab for the language. Then use lpksetup again to remove the language.

Done!

Try your role or feature install again.

This is how I ended up fixing the problem.

Took me a while to find the proper language pack for Server 2016, the windows 10 packs — no work-y... Had to download an ISO from the Microsoft licensing site to get the correct one!

Hope this helps someone!