I have Quicken Mac 2019. I do
Edit Security > Options > Import History from CSV file...
I give it a file:
Date,Close
08/04/2013,0.005874
08/05/2013,0.005875
08/06/2013,0.005637
08/07/2013,0.004669
(2000 more lines)
I get:
"File selected did not have the required format / The provided CSV header was invalid."
I can fiddle with the line endings. I can give more header fields. No matter what I do, it doesn't like the header.
What does Quicken want here? Why is it failing?