It seems that a specific mac slingplayer is not provided anymore. Instead of this the browser plugin solution is provided. The plugin requires access to the watch.slingbox.com homepage, even if the sling box is available in the local network.
I cannot understand that internet access is a requirement to sling. How can I watch content from my slingbox Solo from my local network when I do not have internet access?
If you are using the web-based SlingPlayer application on your computer, you will need to get the Internet service. Otherwise, you will not be able to get the Slingbox up and running.
On the other hand, the following link will allow you to get the SlingPlayer software version for Mac computers.