Hi AlanGlenister,
Brilliant troubleshooting! You hit the nail on the head: you are running into the exact nuance of how 24H2 resolves capabilities from local sources.
Your folder structure is completely fine. The problem is that the Add-WindowsCapability engine in 24H2 has a nasty habit of failing to parse the new combined LoF metadata correctly when pointed to a local drive. This is especially true if your base OS language (like your en-GB) differs from the default en-US mappings it tries to resolve first. The engine gets confused, gives up, and falsely claims the CABs are missing even though you are staring right at them.
Here is the bulletproof bypass: Stop relying on the buggy capability resolver, and forcefully inject the CAB files directly into the OS using DISM.
As you correctly deduced, you need both the language-neutral package (~~) and the language-specific satellite package (~en-GB~).
Run this exact command in an elevated Command Prompt or PowerShell to bypass the capability engine entirely:
DISM.exe /Online /Add-Package /PackagePath:"C:\AHG\FoD\Microsoft-Windows-ActiveDirectory-DS-LDS-Tools-FoD-Package~31bf3856ad364e35~amd64~~.cab" /PackagePath:"C:\AHG\FoD\Microsoft-Windows-ActiveDirectory-DS-LDS-Tools-FoD-Package~31bf3856ad364e35~amd64~en-GB~.cab"
(Note: Just double-check the exact filenames in your C:\AHG\FoD folder to ensure the architecture amd64 and the hash string 31bf3856ad364e35 match what you actually have).
This direct injection method forces Windows to unpack and install the features without querying the broken FoD metadata structure. Give this a try and let me know if it finally gets those AD tools installed for you!
If this helps you bypass the 24H2 FoD headache, please consider clicking "Accept Answer". It will definitely save other admins from pulling their hair out over this exact same bug!
Tracy.