I think the original poster just needs to repost their viz. I notice this with older workbooks on Public as well but newer ones seem to work fine. The workbook can be downloaded in this case, so just download the workbook and extract it locally in Tableau.
In general, I need a reliable way to get CSV data from any viz on any server (T public or T Server). I got stuck at getting filtered CSV data from this particular viz, so I thought it would be a good example to use in my request for help.
Downloading the workbook would help with figuring out the internal structure of a particular viz, but this is not my intent. Think of it from the system integration perspective: imagine you are building a hub that automatically pulls CSV data from specified Tableau URLs. I asked a similar question here, just in case: CSV export and data filters .