We have just started the effort to upgrade our Lync Online Dedicated customer deployments to Lync Server 2013. As we prepare the customers for this task, the minimum client versions have to be communicated and there is an interesting discrepancy between the version displayed in the Lync for Mac user interface and the version the client submits on the wire to the server.
We communicate that Lync for Mac 14.0.4 is the minimum required version, although the customer I am working with today reported problems fixed in 14.0.5 which I told them they should treat as the minimum version.
The user report we provided has the following User-Agent string, notice the version inserts a 0 in front of the 5.
UCCAPI/4.0.7323.0 MC/14.0.0524.5 (Microsoft Lync for Mac 2011)
Turns out that 14.0.0524.5 is the 14.0.5 client version, the reason for the different syntax is that 0524 represents the month day of the release May 24, neat huh?
End users can generally trust their client version displayed in the user interface, however every once in a while it may be required to review the User-Agent string say like with 14.0.4 which had 2 releases which if I recall correctly was due to signing the wrong version and needing to be updated.
UCCAPI/4.0.7323.0 MC/14.0.0409.4 (Microsoft Lync for Mac 2011)
UCCAPI/4.0.7323.0 MC/14.0.0415.4 (Microsoft Lync for Mac 2011)
I wouldn't recommend 14.0.5 as minimum. It has issues with making and receiving calls after certain idle time. See comments at blogs.technet.com/.../lync-for-mac-14-0-5.aspx and entries at social.technet.microsoft.com/.../cant-start-a-video-call-more-than-once-in-lync-for-mac-2011