#1 - Jan. 17, 2015, 1:53 a.m.
We're still in the process of deploying the latest build (19480) to PTR realms but unfortunately there are significant issues with the Mac version of this build.
When updating via a Mac OS, the Battle.Net App may hang at "Fetching Encoding table", or a similar message. It's possible PC users may get stuck here as well, but our testing indicates that the PC update will eventually go through.
Additionally, if you are able to patch up a Mac client I wanted to let you know ahead of time there's some Mac-specific UI issues. These issues were caught several days ago, but weren't able to be fixed before this build was generated.
Apologies for any inconvenience.