Thanks for using our answers forum! I'm sorry to hear that you're having this issue connecting to your Slingbox from your SlingPlayer for Windows Phones. You do need a Slingbox 500, 350, PRO HD or SOLO for use with this SlingPlayer. You also need to make sure you are meeting the bandwidth requirements from both the home location of the Slingbox as well as from any mobile or WiFi network you are using to access the Slingbox remotely from. If you are meeting these requirements and your Slingbox is properly set up from the home location for internet viewing, you shouldn't have any issues.
Here are the requirements for SlingPlayer for Windows Phones:
Hope this helps!
The Sling Moderation Team
What happened to support for the DISH Network Sling adapter? It isn't like this is some antique technology! It is still sold by DISH and advertized to provide mobile access to the DISH Network. Worked fine on my antique iPhone 4. Continues to work on my wife's iPhone 4S and iPad v3. Some reason you are not supporting the Windows Phone 8 platform (or the Windows 8 PC platform for that matter)?