UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa0 in position 63: invalid start byte

[sentry]

Sentry Issue: ASYNC-BACKEND-18

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa0 in position 63: invalid start byte
  File "/application/core/workflow.py", line 465, in csv_to_json
    data_list = list(csv_data)

Cannot process file as CSV 

[pooleycodes]

Comment in Sentry: Looks like they've submitted a pdf - not accepted - could be worth a clearer error message