Newsletter returns empty when events selected

I bought the premium optin of the newsletter plugin to integrate events from Events Manager into Automated emails. I selected the EVents Manager theme under Automated Newsletters and selected the categories of events to displays
However, the newsletter is empty. Message displayed:
“The theme has not found new content since last newsletter to generate a new message.”
There has been NO newsletter sent!
I would appreciate your help as soon as possible.

Thank you