The events were not added because you entered an incorrect format for the start and end date of the event. You can find more about the format here: https://mdbootstrap.com/docs/standard/plugins/calendar/#section-event-formats

Here you will find a fixed snippet that works: https://mdbootstrap.com/snippets/standard/grzegorz-bujanski/4056945

I also recommend updating the calendar plugin to a newer version. In the last version, we improved the display of short events.

When it comes to returning information with errors - we've decided to not add error handling on our side. It would require adding many lines of code, which would significantly increase the size of our package. This would make the page loading slower. Which is of particular importance for mobile devices