Events generate errors in Structured Data Testing Tool

Calendar displays on page well,

When I look at this page using the Structured Data Testing tool, I see error, so we will not see any rich snippets in Google SERP

This is an example of one of our pages seen in Structured Data Testing tool
https://developers.google.com/structured-data/testing-tool?url=http%253A%252F%252Fpub340.ca%252Fevents%252Fopen-mic%252F

Am I missing something?

I have tried to add schema to the calendar item – but I have had not luck. Simple Calendar is generating some schema that I can not get at.

Any ideas?

https://ww.wp.xz.cn/plugins/google-calendar-events/