I am using Firefox on a MacBook Air with OS 11.6.2 in order to use online banking in Portugal. I need and have generated a Digital Certificate at the bank, but when I try to import it so that the bank with recognize my device it gives me an error messages of " Unable to import this item" and Unknown format in input". I spoke to Apple support already and they suggested that I speak with you first to see if you would know why this problem is occurring. I have been using this computer in the past to access the accounts, but because my Digital Certificate has now expired I am required to generate a new one. I have attempted this 9 times in the last two days without success. I have also spoken with the bank in Portugal and they were not able to determine why I cannot import/save this certificate to my computer. Also the MacBook Air is from early 2014.