Oracle has made the business decision to terminate all AddThis services effective as of May 31, 2023. Read More
This decision was announced in April, but i didn't get any information from AddThis before one user of iCagenda informed me on 3rd June...
All code associated with AddThis is therefore removed and iCagenda's social sharing is currently discontinued until a new solution is offered.
I truly recommend to update iCagenda to version 3.8.18, in order to remove obsolete code used by AddThis integration.
In the meantime, you can use a third-party extension for social sharing (JED) or use the sharing functionality of your site template if it includes one.
Sorry for the inconvenience beyond our control.