Steve
Name the csv file with the name of the Alignment that you want to associate it with - ie if you have an alignment with the name HAL that you want to use - then call the file HAL.csv.
If there is only one alignment in the project - we associate the CSV file with that one automatically. If there is more than one alignment then the imported csv file has to have an alignment name so we know which one to add the data to.
There is a full document / case on the BC-HCE (CEC Forum) that I have uploaded previously that has example data and full description notes if you need it.
Hope this helps
Alan Sharp