troubleshooting windows update issue - how to read cbs.log?

Question

Hi heroes,

May I know does Microsoft has guides on how to read cbs.log?
I'm troubleshooting a windows 10 20H2 KB5003637 install failure issue.

part of the cbs.log output is something like below:
49814: 2021-06-16 13:51:27, Info CBS Child cab SSU-19041.1022-x64-express.cab extracted from cab location \?\C:\Program Files (x86)\360\360Safe\hotfix\windows10.0-kb5003637-x64-express_32a78bd4bcd40b9361011a4e648e4f7a30fde84c.cab and placed in sandbox \?\C:\Users\
49853: 2021-06-16 13:51:31, Info CBS Child cab Windows10.0-KB5003637-x64.cab extracted from cab location \?\C:\Program Files (x86)\360\360Safe\hotfix\windows10.0-kb5003637-x64-express_32a78bd4bcd40b9361011a4e648e4f7a30fde84c.cab and placed in sandbox \?\C:\Users\
49853: 2021-06-16 13:51:31, Info CBS Child cab Windows10.0-KB5003637-x64.cab extracted from cab location \?\C:\Program Files (x86)\360\360Safe\hotfix\windows10.0-kb5003637-x64-express_32a78bd4bcd40b9361011a4e648e4f7a30fde84c.cab and placed in sandbox \?\C:\Users\
49859: 2021-06-16 13:51:32, Info DPX ProvideRequestedDataByFile failed, Response file Name: \?\C:\Users\xxx\AppData\Local\Temp\~1d76273a5f4a835-4484\Windows10.0-KB5003637-x64.cab
49877: 2021-06-16 13:51:37, Info DPX Extraction of file: update.ses failed because it is not present in the container (\?\C:\Users\xxx\AppData\Local\Temp\~1d76273a5f4a835-4484\Windows10.0-KB5003637-x64.cab).

But it is really hard to understand these logs, any tips on how to read the cbs.log pls? thanks!

Answer 1

Hi,
It’s best to open it in text editor that can handle the big size
then, search for , error
(comma space error), and then see the details and if required, move up few lines and read the info lines.
Why is Update Installation Failing: Eliminating the Usual Suspects
https://techcommunity.microsoft.com/t5/core-infrastructure-and-security/why-is-update-installation-failing-eliminating-the-usual/ba-p/1534024
https://blog.rmilne.ca/2021/02/10/unable-to-install-windows-updates-or-windows-components/?utm_source=rss&utm_medium=rss&utm_campaign=unable-to-install-windows-updates-or-windows-components
Hope this helps and please help to accept as Answer if the response is useful.
Best Regards,
Carl