Error 500 Creating Dataset with REST API Console (http://docs.powerbi.apiary.io/)

I have successfully used the Power BI REST API console (http://docs.powerbi.apiary.io/) to create a dataset.  However, when I attempt to work with the dataset in the Power BI service, I receive a code 500 error "the dataset could not be loaded".  I'm a newbie with this, so any help would be great.  Thanks