[German]Bad news for Mac users who use Parallels virtualization software in macOS to test Windows 10 Insider Preview builds. Parallels Standard no longer supports Windows 10 Insider Previews in the Beta Channel because the manufacturer has secretly removed a required feature.

Virtualization Software Parallels

Parallels Desktop for Mac (formerly Parallels Workstation for Mac OS X) is a virtualization software from Parallels for macOS on Intel processors. As host operating system Mac OS X is supported, as guest operating system a variety of 32 bit operating systems, from version 6 on also 64 bit, for x86 is supported (among others Windows, Linux, *BSD, OS/2, Solaris/86 or Mac OS X Lion). The virtualization software is quite popular on the Mac.

Support for Windows 10 beta channel builds dropped

PKCano now indicates a major change in Parallels at askwoody.com. He has been in the Windows 10 Insider program since October 2014 and has been running the Insider Fast Ring/Dev Channel previews in Parallels Standard Edition VMs on Macs without any problems during this time. Parallels v15 has hosted the VMs flawlessly since late 2019.

Starting with Windows 10 Pro Insider Build 20175.1000, these builds suddenly stopped installing. This is a common problem with virtualization software, usually it is removed at some point by updating the virtualization software.

Parallels recently released version 16, and PKCano hoped this would solve the problem. He upgraded on August 14, 2020. The Insider Preview builds of Windows 10 still could not be installed. Therefore he opened a support ticket at Parallels. During a remote session with a Parallels engineer, he told the user to contact Microsoft. Because it was an MS problem. Subsequently, PKCano received a reply from Parallels as a mail:

We have escalated the issue you reported to the Development Team and they are working to address it in one of the future builds of Parallels Desktop for Mac.

While we do not have ETA for the fix, it has been prioritized appropriately and you can track the changes in the product at the corresponding knowledge base article page.

Sounded good at first. But then there were more details in the Parallels forum when a user complained that the Windows 10 Preview Build 20175.1000 under Parallels failed with the installation error 0xc1900101. In the thread Parallels Support replies:

Enabling nested virtualization helps in updating to latest Windows Insider build which is only available with Pro and Business subscription. As you are testing Windows beta versions as a professional using Pro is the right choice and will have more features compared to the standard edition.

Nested Virtualization is required to support the Windows 10 Insider Preview. This feature has been limited to Parallel Pro, the standard edition does not support it. So the possibility to test Windows 10 Insider Preview builds from the beta channel in Parallels has gone.

Addendum: A speaker from Parallels did send me the following statement.

"Nothing changed in the scope of Windows Insider support in Parallels Desktop 16. The current issue is not related to the Parallels Desktop version 15.1.3, as it's a new one. To work around this issue, users need to use the nested virtualization feature that comes in Pro Edition. Once a fix is available, it will be included the next Parallels Desktop update and shipped to all Parallels Desktop editions, including the Standard Edition."