SHD allows for offline update from any version of 4.0.x to any version of 4.0.x.
There is a known issue when preforming the SHD 4.0.9 update. You are only able to update from 4.0.7 or 4.0.8 to 4.0.9.
Skyline Health Diagnostics (SHD)
Offline patch builder relies on shd-download to pull the previous patches. As the shd-download is no longer working, this stage appear to be failing silently.
This will be fixed with a later version of SHD.
Workaround: The workaround for this issue is to preform a migration to SHD version 4.0.9