PLEASE COPY THIS INTO YOUR BROWSER
steam://install/717190/
or
https://steamdb.info/app/717190/subs/ - press 'FREE' (top right)
(thanks to Siight and others for alerting me tto this)
___
Steam team alerted to this issue: apparently it happens a lot, a problem with their deployment platform - so all I can do is apologise on their behalf.
~~~
Enjoy the free pizza while I fish out my lost d20 and lucky brass pig.