In Parallels Desktop 12 for Mac (Pro Edition), version 12.2.0, under macOS Sierra 10.12.5, I cannot seem to download a Chromium OS virtual machine to use as a guest. From the main Parallels Desktop menu, I select File > New, and at the bottom of the Parallels Wizard window that opens click on "Download Chromium OS" and click Continue. In the resulting "Chromium OS Free" window, I click Download. The window disappears and that's all. I don't see any indication of downloading, and I don't find any file that seems to be the download, even after waiting 30 minutes. What's wrong? And in what location should the download appear?