Latest Release 6.0.20154.0 has broken CalDAV, ever event acceptance fails

With the lastest release of emClient (6.0.20154.0) they have broken the CalDAV functionality.  It worked fine up until now.

When I accept an event sent from a third party,  the event does not get into my calendar and then it fails to reply to the sender, producing a “PreCondition Failure” on the server.  Now every time I restart the client I get popup message boxes for every event I have accepted since the upgrade, now getting to be unusable.  The option are update later, ignore or delete.  The first is the only viable one, I need it in my calendar, but it does not work. 

Besides the constant request to relogin to yahoo account, this is the error that will cause me to abandon emClient.

FYI:  I’m a PRO user and have entered tickets (2) at the Enterprise level, and they are not answering me there either.  This is a big problem, and no-one from eMClient is getting back to me.  If anyone has any idea’s please, I cant go much longer this way.  I need my Calendar to work.

Hi, if you’ve entered a ticket as a pro user, please be patient, your ticket will be answered soon.

Thank you for understanding,