Sitecore expects an integer value to identify the channel id, which is used to identify the online store to retrieve from the channel database.
The problem I faced was that the neither the Microsoft Ax Partner or the customer could give me the id, all they could find was the name which was a string value!
But fear not the following SQL statement which you can run against the channel database will show you all the channels and their assoicated id 🙂
SELECT TOP 1000 [NAME] ,[CHANNELID] ,[OPERATINGUNITNUMBER] ,[SERVER] ,[DATABASE] ,[ISPUBLISHED] ,[ISLOCAL] ,[CONNECTIONSTRING] FROM [AsyncClientDB].[crt].[STORAGELOOKUPVIEW]
Also ensure that channel is in fact published otherwise Sitecore can not use it, hope this helps Alan