error CS0234: The type or namespace name 'Windows' does not exist in the namespace 'Microsoft'

Hi, I am new at unity so it might be a stupid question.

I'm now certain if it this issue is a unity issue but I still want to ask you because I can't resolve it.

I imported a unity project. Unfortunally one error appears I can't solve (See attachement).

Is it possible that a MRTK File is missing?

Do you have a solution?

Thanks

 

That line should be activated when targeting Windows Store Apps.
You should follow the MRTK guide in order to get started.
https://microsoft.github.io/MixedRealityToolkit-Unity/Documentation/Installation.html