I've been experiencing this issue and I haven't been able to find anything useful on google at all. I've been able to bypass this error message by creating an unattend.xml with just the product keys in it. Here's what it looks like:
<?xml version="1.0" encoding="utf-8"?>
<unattend xmlns="urn:schemas-microsoft-com:unattend">
<settings pass="windowsPE">
<component name="Microsoft-Windows-Setup" processorArchitecture="x86" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<UserData>
<ProductKey>
<Key>W269N-WFGWX-YVC9B-4J6C9-T83GX</Key>
</ProductKey>
</UserData>
</component>
<component name="Microsoft-Windows-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<UserData>
<ProductKey>
<Key>W269N-WFGWX-YVC9B-4J6C9-T83GX</Key>
</ProductKey>
</UserData>
</component>
</settings>
</unattend>
Copy the above xml into a new file called autounattend.xml and place the file into the root directory of your USB/DVD.
The product key it uses is a default upgrade key. I've been able to install windows and change my product key once installed using this method.