Thanks. The same Notes appear in the R81 Web Console admin guide.
I am trying the Dynamic Package download. That is supported (as per the notes).
Dynamic Packages (self extracting executables) is the recommended package.
There is a Package Repository in the Harmony Endpoint Web Management portal and dynamic packages can be uploaded in there (Policy > Export Package > Package Repository > + ).
From there a new exportable package can be created and then can be downloaded (or at least it should be downloadable).
Testing so far:
It looked like my problem may have been caused by the Chrome browser (version 108.0.5359.71). Error message was from Chrome and not CP. I just updated it to 108.0.5359.95.
Edge browser worked first time, but has also failed twice 2/3 times now (with error Couldn't download - Network issue).
I will have to do some more testing.
Bit of a pain that the download takes a while to Prepare the package before the Download option appears, every time the Download button is used.
Why does it 7z prepare the package each time? <-- Question for R&D there.