When you upgrade from an older version of the InfoBridge Synchronizer to the V2 Synchronizer you can use the Clean tool which is provided in the new setup.
But in some situations a manual cleaning of Outlook/Exchange is needed.
In cases of other software than the InfoBridge Synchronizer being in use it is advisable to manualy clean the Outlook/Exchange Calendars.
Attached you will find a guide on how to perform this clean action.