Intermittent Catchable Fatal Error

My client is seeing an intermittent error when pulling in event information from Constant Contact onto their site’s events pages.

I don’t see it when I test it. But a rep at Constant Contact also saw it when the client called them looking for information, so it’s not an internal server issue. The CC rep suggested it may have something to do with “autofill commands”.

Here’s a link to one of the event pages that has been showing the error: https://www.karenannquinlanhospice.org/events/butterfly-release-celebration-warren-county/

Here’s a link to a screenshot that shows the error message: https://www.karenannquinlanhospice.org/wp-content/uploads/error-screenshot.png

Can anyone shed any light on this?

https://www.ads-software.com/plugins/constant-contact-api/