CarDAV Yahoo contacts sync failed

Hi All, sync my yahoo contacts seems not working. I receive this error:
and in the status bar there is this error message: “object refernece not set to an instance of an object”.
I’m running emClient 6.0.24144.0 under Windows 10 1511 build 10586.36

I’ve tried to delete the account and reinsert the username and password, but with no success. Please, it would be possible to have an help on this?

I have exactly the same problem.  I want to synchronise 3 Pcs (W10, 7 and Vista) all running EM Client.  The server is BT Yahoo.  Can I do this via Yahoo or is there another way?