I get the same problem sometimes. You may want to try clearing cookies/browser cache/etc. I am trying to upload the JSON VBO here, but it's just saying Upload Failed.
Try going to the Digital Exchange from a different browser. Chrome seems to work consistently for me. Meanwhile, maybe someone else can upload the JSON VBO here for you. I'm not sure what's going on with the site.
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Dave Morris
3Ci @ Southern Company
Atlanta, GA
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Dave Morris, 3Ci at Southern Company