!HForm errors

They cannot be individual files ….

You are, of course, quite correct.

I think the standard RISC OS image was reduced multiple times to fit on the “smallest 2 GB SD card ever seen in the wild”.

Entertainingly ROD’s Direct image has a similar problem, see here. (Scroll down past all the INET stack stuff.) The image is described as 16/32GB. The unzipped img file is 16.01GB, too big for my 16GB card which in reality is only 15.6GB. On the bright side 16.01GB is quite a bit bigger than ROOL’s 1875M image, which this Mac reports as 1.97GB.

The unzipped img file is 16.01GB, too big for my 16GB card which in reality is only 15.6GB.

This sounds like confusion between power-of-two gigabytes used by memory etc, and stupid-base-10 gigabytes used by storage devices.