You should be able to get the version 5.8 compatible version ("the old versions") of KiViR if you login to the User Area and go to "downloads".  At the bottom of the page you'll find a link to "Legacy" instruments, which is where you will find the download file for version 5.8 compatible KiViR.

That said (and I don't work for Modartt), I'd strongly recommend updating to the latest version of Stage, which has noticeable improvements in all the instruments, IMO.  Updates are pretty cheap (again, IMO).

Thanks, that fixed it.

I would gladly buy the new version. But I am a full-time musician and, by definition, broke.

Pianoteq Stage version 5.8.1

I suspect what has happened is that the KiViR (free) set was updated to require version 6+ of Pianoteq recently.

You should be able to get the version 5.8 compatible version ("the old versions") of KiViR if you login to the User Area and go to "downloads".  At the bottom of the page you'll find a link to "Legacy" instruments, which is where you will find the download file for version 5.8 compatible KiViR.

That said (and I don't work for Modartt), I'd strongly recommend updating to the latest version of Stage, which has noticeable improvements in all the instruments, IMO.  Updates are pretty cheap (again, IMO).

Hi,
I know this did work in the past (albeit on a different machine) but I can no longer install the free .ptq files by dropping them on the interface. I do get the confirmation ("...has been copied...") but nothing changes about the available presets. The free instruments just do not show up, even after restarting the software.
What could I be doing wrong?

You need to state your version number and whether it's stage, standard or pro, as well as what operating system version you have.  No one can even verify your problem properly without knowing these things.

This happens on Windows 10 with Pianoteq Stage version 5.8.1