What does the Break event link button do?

Break event link button will appear on invoices that were created in an event batch or any additional invoice that you manually associated with an event using Associate with event button.

Breaking an event link is not recommended unless there is an event incorrectly associated with an event. Invoices created in an event batch will typically never need the link broken. This button will be used more often after someone manually associates an invoice with an event and then changes their mind.