Sitecore 8.0 - ERROR EmailCampaign: Failed to send 'Subscription Notification' to 'xdb:14c0c3e8-afd6-4344-98ab-5b86dcb4dd30'

Question

I'm working on Sitecore 8.0 rev 150621 and I'm getting the following error message on my logs.

MessageTaskRunner worker thread 9 05:07:03 ERROR EmailCampaign: Failed to send 'Subscription Notification' to 'xdb:14c0c3e8-afd6-4344-98ab-5b86dcb4dd30'.

In the fresh logs also I'm getting this error couple of times. I think Sitecore tries to send subscription email message to the subscriber: 14c0c3e8-afd6-4344-98ab-5b86dcb4dd30.

Does anyone have an idea about how to find this user on the Sitecore xDB ? I tried to find it on the Analytics mongoDB database using the following query:

db.Contacts.find({'_id' : '14c0c3e8-afd6-4344-98ab-5b86dcb4dd30'})

But I couldn't find any results. Am I doing it correctly ? or Am I looking at the wrong database table or field ?

Please advice me on this.

Thanks.

UPDATE

Detail error:

MessageTaskRunner worker thread 3 12:45:46 ERROR EmailCampaign: Failed to send 'Subscription Notification' to 'xdb:14c0c3e8-afd6-4344-98ab-5b86dcb4dd30'.
MessageTaskRunner worker thread 3 12:45:46 ERROR EmailCampaign: Message sending error: System.InvalidOperationException: Custom Data does not contain specified key.
   at Sitecore.Analytics.Automation.Data.AutomationStateContext.UpdateCustomData(String keyName, Object value)
   at Sitecore.Modules.EmailCampaign.Core.Gateways.DefaultAnalyticsGateway.EnrollOrUpdateContact(Contact contact, Guid planId, Guid stateId, EcmCustomValues customValues, String[] validStates)
   at Sitecore.Modules.EmailCampaign.Core.Gateways.DefaultAnalyticsGateway.EnrollOrUpdateContact(Guid contactId, Guid planId, Guid automationStateId, EcmCustomValues customValues, String[] validStates)
   at Sitecore.Modules.EmailCampaign.Core.Analytics.AutomationStatesManager.EnrollOrUpdateContact(Guid contactId, Guid planId, String stateName, EcmCustomValues customValues, String[] validStates)
   at Sitecore.Modules.EmailCampaign.Core.Dispatch.DispatchManager.EnrollOrUpdateContact(Guid contactId, DispatchQueueItem dispatchQueueItem, Guid planId, String stateName, EcmCustomValues customValues)
   at Sitecore.Modules.EmailCampaign.Core.Dispatch.DispatchTask.OnSendToNextRecipient()

Answer 1

You cannot query _ids as strings, since they are stored in a special binary format. The conversion is handled by the C# driver. There are a couple ways to query GUIDs from the mongo shell. Please take a look at these StackOverflow answers:

• How do I use a guid in a mongodb shell query
• Get BinData UUID from Mongo as string

In regards to the error you are receiving, there has to be an exception logged with more details on what actually happened.