During mailbox or calendar synchronization to Exchange 2013, "Value cannot be null" appears after an autodiscover response in the MAgE.log for the corresponding agent.
The log lines may appear something like this:
2015-06-05 13:55:37.5869 Px5A4 Tx18 A1 C8 M7 Trace EWS: Connect end
2015-06-05 13:55:37.6025 Px5A4 TxF A1 C8 M4 Error System.ArgumentNullException: Value cannot be null.
Parameter name: uriString
at System.Uri..ctor(String uriString)
at Dell.MigrationManagerForExchange.General.Ews.Autodiscover.GetEwsUrlInternal(String emailAddress, NetworkCredential creds, Uri& autodiscoverUrl, Boolean enableScpLookup)
at Dell.MigrationManagerForExchange.General.Ews.Autodiscover.GetEwsUrl(String emailAddress, NetworkCredential creds, Uri& autodiscoverUrl, Boolean enableScpLookup)
at Dell.MigrationManagerForExchange.General.Ews.EwsSessionCreator.DiscoverUrl()
at Dell.MigrationManagerForExchange.General.Ews.EwsSessionCreator.get_Url()
at Dell.MigrationManagerForExchange.General.Ews.EwsSessionCreator.GetExchangeService()
at Quest.MigrationManager.Exchange.MigrationConnectors.EwsSyncConnector.get_Exs()
at Quest.MigrationManager.Exchange.MigrationConnectors.EwsSyncConnector.ConnectInternal()
at Quest.MigrationManager.Exchange.MigrationConnectors.EwsSyncConnector.Connect()
All autodiscover information and SCP information, including servicebindinginformation are verified as valid and proper.