I am using my own self-generated certificate authority certificate to create certificates for my websites and IMAP/SMTP communication.
When I tried to import my CA certificate in Chromium I got an error message saying "Unable to parse file":
A very descriptive error message indeed, but I finally figured out what the problem was. I had previously imported a CA certificate with the same common name (CN). When I removed the other certificate Chromium was suddenly able to parse the file.