You can share your contact card or another person’s contact card as a vCard file (.vcf) so that others can add it to their list of contacts. You can share cards by email, text, or another method.
It is not clear as to what error message do you get when you save a vCard File?
Which is your default Contacts Account? Google, iCloud, AOL, Exchange, Outlook, Yahoo, or any Other email account.
Unlike some Android devices, contacts are neither stored locally on an iPhone nor in SIM. They are synced to an email account that you had Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other