I have encountered what looks like *two* bugs in the .csv export function on macOS.
I am trying to write a .csv file to the top-level directory of a mounted encrypted sparse image. That is, I have a 500MB file on my desktop, which when I click on it and feed macOS a password, gets mounted as /Volumes/passwords.
I select Enpass's Export menu item, choose CSV, and browse to /Volumes/passwords. Then I click the export box, enter my master password and Enpass says it has successfully expor