Installing the Remote System Administration Tools on a Windows 10 1903 system that uses System Center Configuration Manager to receive Windows updates seems to be challenging. The process of pulling the RSAT bits down from Windows Update in my experience was not succeeding – perhaps because the SCCM WSUS instance did not have them.
The CBS.log showed:
CBS Exec: Failed to download FOD from WU, retry onece. [HRESULT = 0x800f0954 - CBS_E_INVALID_WINDOWS_UPDATE_COUNT_WSUS]
Some solutions online seemed to suggest temporarily switching the Windows Update source in the registry to Windows Update (online) rather than WSUS, but editing the registry this way and upsetting the software update system seemed… unwise.
I ended up doing it a different way: downloading the Features on Demand DVD ISO from the Volume Licensing Service Center (in my case, SW_DVD9_NTRL_Win_10_1903_64Bit_MultiLang_FOD_1_X22-01658.ISO), mounting the ISO and using this modified version of Martin Bengtsson’s script to install the components from that ISO without contacting Windows Update.
With any luck, this might help someone else.