Table data could not be loaded in sciview

Hope this isn't a dumb question, but how do I get the error “Table data could not be loaded The result of table command is empty” to stop. I think it's affecting visualizations and data wrangler. I've tried with different versions of python and on multiple computers. It used to work in Pycharm too, but just tested it out and it did not work there either with the same error. 

CSV file is literally:

a,b,c
1,2,3
4,5,6

Let me know if it's something simple to change.