Persistence issue

I am having an orchestration which is set to atomic and the scope transaction is set to none. variables are declared outside the scope. I call a custom.dll from the orchestration where the methods are marked as serializable.

[Error Message]

Uncaught exception (see the ‘inner exception’ below) has suspended an instance of service ‘HandshakeInt.handShakeOrch(a95b4c47-850a-53c6-127a-e5cefeda643b)’.
The service instance will remain suspended until administratively terminated.
InstanceId: 7a7deabe-e559-4016-b233-4f1afe10177a
ShapeId: 00000000-0000-0000-0000-000000000000
Exception thrown from: segment 1, progress 0
Inner exception: Exception occurred when persisting state to the database.

Exception type: PersistenceException
Source: Microsoft.XLANGs.BizTalk.Engine
Target Site: Void Commit()
Help Link:
The following is a stack trace that identifies the location where the exception occured

at Microsoft.BizTalk.XLANGs.BTXEngine.BTXXlangStore.Commit()
at Microsoft.BizTalk.XLANGs.BTXEngine.BTXXlangStore.ScheduleComplete(Boolean terminate)
at Microsoft.BizTalk.XLANGs.BTXEngine.BTXService.ScheduleComplete(Context ctx, Boolean finalPersisting, Boolean terminate)
at Microsoft.XLANGs.Core.Service.Persist(Boolean dehydrate, Context ctx, Boolean idleRequired, Boolean finalPersist, Boolean bypassCommit, Boolean terminate)
at Microsoft.XLANGs.Core.TransactionalContext.OnCommit()
at Microsoft.XLANGs.Core.AtomicTransaction.OnCommit()
at HandshakeInt.handShakeOrch.segment1(StopConditions stopOn)
at Microsoft.XLANGs.Core.SegmentScheduler.RunASegment(Segment s, StopConditions stopCond, Exception& exp)
Additional error information:

A batch item failed persistence Item-ID 83efbe3c-e795-4217-bcf8-8b3b0a0b1cc2 OperationType MAIO_CommitBatch Status -1061151998 ErrorInfo The published message could not be routed because no subscribers were found. Please use the Health and Activity Monitoring (HAT) tool to diagnose this situation. .

Exception type: PersistenceItemException
Source:
Target Site:
Help Link:
The following is a stack trace that identifies the location where the exception occured

Additional error information:

A batch item failed persistence Item-ID 7a7deabe-e559-4016-b233-4f1afe10177a OperationType MAIO_InstanceComplete Status 12589892 ErrorInfo .

Exception type: PersistenceItemException
Source:
Target Site:
Help Link:
The following is a stack trace that identifies the location where the exception occured

Additional error information:

Failed to publish (send) a message in the batch. This is usually because there is no one expecting to receive this message. The error was The published message could not be routed because no subscribers were found. Please use the Health and Activity Monitoring (HAT) tool to diagnose this situation. with status -1061151998.

Exception type: PublishMessageException
Source:
Target Site:
Help Link:
The following is a stack trace that identifies the location where the exception occured

Additional error information:

[/Error Message]