Exchange logs are not truncating either as part of the nightly job or when forced manually via the AppAssure GUI. AppAssure and Exchange are both patched up to appropriate levels and the AppAssure snapshot with log truncation job appears to run successfully..
Event ID 2007 may be present in the Application log on the exchange server, with an error similar to Information Store (15976) Shadow copy instance 19 aborted. .
Running "Vssadmin list writers" from a CMD prompt may list the 'Microsoft Exchange Writer' as being Failed or Waiting for completion
These symptoms can be visible when a third party application that also uses VSS writers is scheduled to run at a similar time to the AppAssure schedule. The backup can complete but because the Microsoft Exchange writer is failed or timed out the exchange databases do not freeze successfully and consequently logs will not truncate.
To resolve the issue disable or reschedule the 3rd party application so it cannot run during AppAssure's nightly job schedule the time of which can be confirmed by :
1) Open the AppAssure Core GUI and go to Configuration
2) Choose Settings
3) Confirm the nightly job time in the Nightly Jobs section
4) Additionally reset the Microsoft Exchange VSS writer by rebooting the Exchange system