Archive Manager Exchange Store Manager Service error - "Object reference not set to an instance o (4306501)

Exception Source: AfterMail Exchange Store Manager Service
Exception Type: System.NullReferenceException
Exception Message: Object reference not set to an instance of an object.
Exception Target Site: get_xd1d7ebede293dbf9
Date and Time: <Date>
Machine Name: xxxx
IP Address: xx.xx.xx.xx
Current User: xx\ArchiveMgr_ESM
CLR Version: 1.1.4322.2300
Platform (version): Win32NT (5.2.3790.0)
Application Domain: Archive Manager Exchange Store Manager Service.exe
Assembly Codebase: file:///C:/Program Files/ArchiveManager/Archive Manager Exchange Store Manager Service.exe
Assembly Fullname: AfterMail Exchange Store Manager Service, Version=3.6.1.20, Culture=neutral, PublicKeyToken=fee0657bdd36eadb
Assembly Version: 3.6.1.20
Exception Source: AfterMail Exchange Store Manager Service
Exception Type: System.NullReferenceException
Exception Message: Object reference not set to an instance of an object.
Exception Target Site: get_xd1d7ebede293dbf9

---- Stack Trace ----

N/A

WORKAROUND:
None

STATUS:
Waiting for a fix in a future release of Archive Manager

N/A