OSMC Windows installer no longer working

I have re-imaged my Vero 4K numerous times using the Windows installer and a USB stick, never had a problem. I now have a spare Vero and last night tried to re-purpose it as my main TVheadend box, but the experience turned out to be a bit flaky compared to the LE Pi that was previously covering those duties. So I thought I’d do a clean install and start again - except that when I get to final step of the installer to write the image to the stick, I get a non-specific error message and the installer appears to have crashed. I’ve reformatted the stick, disabled anti-virus, tried writing a local image, all to no avail.
Seems very odd that the installer should just die like this. Any ideas?

EDIT: just spontaneously started working again…

Not really. Make sure you run it as an Administrator; although you should be prompted to do this automatically.