Phone numbers missing when importing VCF
I have a Firefox OS smartphone and exported my contacts using the apps Con Backup and PC Sync.
In Thunderbird, I try to import them to the address book, but both VCF files (with multiple entries) created by the apps will not import correctly. I only get the names on one, the other additionally shows the company name, but neither one shows the phone numbers.
Using a text editor, I saw that Con Backup exports a VCF version 4, PC Sync exports it in version 3. My Thunderbird is up to date and I can't imagine that it can't deal with these files?
How can I properly import these VCF in Thunderbird?