[Plugin: Stout Google Calendar] Error 403

Are you able to view the calendar preview within the admin?

I’m not exactly sure why you are getting this message. Typically if the calendar isn’t shared to for everyone to view, you are prompted with a Google login screen. You may want to double check that, within your Google calendar account, the calendar is set to viewable by all.

This 403 error may be an issue with your hosting and the requirements for the plugin. Please refer to “Requirements” section of the Installation Page and verify your hosting meets these items.