Node tokens invalid in context "node type"

Hi,

Using all the most current versions of the involved modules, "Node" tokens all seem to be invalid for "Node Type" context meta tags. As an example, I go to Context UI > Add Context > Condition "Node Type" and choose one type > Reaction "Meta Data". I then open the token browser and choose "[node:author]" for the meta tag "Description" and click save. This is the error I get:
The Description is using the following invalid tokens: [node:author].

Am I missing something here?
Thanks.