Trying to complete the Challenge in the Setting up Lightning Connect module and am getting the following error:

Challenge Not yet complete... here's what's wrong:
There was an unexpected error in your org which is preventing this assessment check from completing: System.ExternalObjectException: data.api.DataSourceException: This data is no longer available. The "phone_plan" table in the external data source is currently unavailable. Try again later or contact your administrator for help

Not sure what the deal is.  Please advise.

Trying to complete the Challenge in the Setting up Lightning Connect module and am getting the following error:

Challenge Not yet complete... here's what's wrong:
There was an unexpected error in your org which is preventing this assessment check from completing: System.ExternalObjectException: data.api.DataSourceException: This data is no longer available. The "phone_plan" table in the external data source is currently unavailable. Try again later or contact your administrator for help

Not sure what the deal is.  Please advise.

I'm following a well written tutorial written by @andymahood__c: http://www.tquila.com/blog/2014/11/17/setting-lightning-connect-and-your-first-external-object

When I get to the step #3 ... "Select Edit on the CustomerID field, ...", I don't see Account (or any objects to relate) listed in the drop down box. I have created the custom field on ACCOUNT named CusotmerID Text(5) and marked it as External ID as follows:

CustomerID CustomerID__c Text(5) (External ID) [Checked]

Any ideas?