If you are working on a structured document and you switch to Author View mode, the document window in FrameMaker turns gray and the document is not displayed.
This issue is resolved in FrameMaker (2019 release). For more information about the latest features in FrameMaker (2019 release), see https://www.adobe.com/products/framemaker/features.html.
In Windows operating system, there is an option to increase the size of applications. If you increase this size to 125% or more, then you might notice gray screen in FrameMaker’s Author View.
Reduce the zoom level in FrameMaker to resolve this issue. Typically, reducing the zoom level to 80% works for most cases. However, if the issue persists, then you can reduce the zoom level further down until the issue resolves.