The CSV Web Data Connector has moved from Heroku to Render. Please update your Tableau connections to use the new URL:
Edit your existing workbook's data source and replace the WDC URL with the new address above.
Run the following commands on your Tableau Server:
tsm data-access web-data-connectors add --name "CSV WDC" --url https://basic-csv-wdc.onrender.com:443 tsm pending-changes apply
Note: this will require a Tableau Server restart.