Thanks for the report and so sorry for the trouble @Michelle_Biscoe. Let’s see how we can help with that:
Can you confirm you’ve followed the tips in this article to set up your CSV before importing it in Asana?
How big is your CSV? (how many rows roughly?)
Could you create a small test CSV file, and verify if you can successfully import it in this project? That would help understand if the issue comes from the CSV file or from Asana