Details of the scenario you tried and the problem that is occurring

With the default ressource that comes with Windows, I have no problem installing the windows feature Dot Net 3.5. But when I install the latest PSDSCResources, the DSC resource fails with Property source in resource WindowsFeature is not a valid property

The source property is required because the source for Dot Net 3.5 is not included locally.

Verbose logs showing the problem

Undefined property source
At line:9, char:2
Buffer:
irectResourceAccess";
};^
insta
+ CategoryInfo : SyntaxError: (root/Microsoft/...gurationManager:String) [], CimException
+ FullyQualifiedErrorId : MiClientApiError_Failed
+ PSComputerName : localhost

Suggested solution to the issue

The DSC configuration that is used to reproduce the issue (as detailed as possible)

    ensure: 'Present'
    name: 'NET-Framework-Core'
    source: '<pathtoshare>\Sources\W2019\Sxs\'   

The operating system the target node is running

Version and build of PowerShell the target node is running

Version of the DSC module that was used ('dev' if using current dev branch)

2.10.0