Are asynchronous CPM "processes" queued ever removed due to errors in processing?
Process Designer, Custom Process Model (CPM) / Service Process Model (SPM)
All product versions
When an asynchronous CPM is triggered the system schedules the event handler to execute using a queuing system. If the first attempt fails for some reason (due to an uncaught code exception or otherwise - such as a server being unavailable), the event handler execution will be retried automatically up to four times. The first retry occurs 90 seconds later, the second occurs 450 seconds later, the third occurs 3,150 seconds later, and the fourth occurs 34,650 seconds later. This is detailed in product feature documentation here.
For more information, refer to the following: