EXM error: Empty strings are not allowed. Parameter name: listId

Question

On a clean install of Sitecore 8.2.1 with EXM 3.4 installed, we're receiving a message of "A serious error occurred please contact the administrator" when attempting to add an Included List in the Recipients section of a new Email Experience Manager campaign.

In the EXM log we see this:

6988 10:58:45 ERROR Empty strings are not allowed.
Parameter name: listId
Exception: System.ArgumentException
Message: Empty strings are not allowed.
Parameter name: listId
Source: Sitecore.Kernel
at Sitecore.Diagnostics.Assert.ArgumentNotNullOrEmpty(String argument, String argumentName)
       at Sitecore.ListManagement.ListManager'2.FindById(String listId)
       at Sitecore.Modules.EmailCampaign.RecipientManager.GetGlobalOptOutRecipients()
       at Sitecore.Modules.EmailCampaign.RecipientManager.GetTargetRecipientCountFromGlobalOptOutList()
      at Sitecore.Modules.EmailCampaign.Core.MessageStateInfo.get_NumSubscribersFromGlobalOptOutList()
   at Sitecore.EmailCampaign.Server.Services.MessageInfoService.GetRecipientsFromGlobalOptOutList(MessageStateInfo info)
   at System.Linq.Enumerable.WhereSelectListIterator'2.MoveNext()
   at System.Linq.Enumerable.WhereSelectEnumerableIterator'2.MoveNext()
   at System.Collections.Generic.List'1..ctor(IEnumerable'1 collection)
   at System.Linq.Enumerable.ToList[TSource](IEnumerable'1 source)
   at Sitecore.EmailCampaign.Server.Controllers.MessageInfo.MessageInfoController.MessageInfo(MessageInfoContext data)

Answer 1

Your problem is that the default settings i.e. the manager root has not been created.

Go to the EXM dashboard, click the Default Settings button and enter the details. The settings are explained here.

When creating the manager root, a Global Opt-Out list is created. This list does not exist in your environment, which is why you're seeing the error.