I did the normal suggestions with a sfc /scannow and also chkdsk and also the dism restore health. After going through CBS file, I could find anything about language packs and the log is a very hard to read. The problem I had was that a lot of the tutorials on how to resolves it are around language packs being the cause. This error corresponds to 'ERROR_SXS_ASSEMBLY_MISSING' if you go searching for it in the CBS logs. To fix the error, run the built-in troubleshooter or perform a DISM and SFC scan, amongst the other methods here. It could be due to corrupt system files, issues with the Windows Update Components, or critical services that are not running. The problem wasn't seen until my production servers were being patched, having patched our DEV and staging servers in the previous weeks. The 0x80073701 error code in Windows 11 is encountered when you try to install an update. I got this error 0x80073701 when installing the September rollup (we patch our environments a week after patch Tuesday releases in case of a issue with a patch).

I had a bit of a head scratcher with two of my servers on last months patching cycle.

0x80073701 fix