Same for me, I wrote a long post about everything I tried: SlingplayerforWeb fails to launch after receiving the latest Windows 10 updates
Came to the same conclusion: One of the Windows 10 updates has messed up the SlingplayerForWeb program. I sure hope Sling Media fixes this ASAP.
I backed out the latest Win 10 updates and my laptop is working again. You have to also stop Win 10 from automatically doing the updates or it will only work for 1 day. Here is a site I used to stop the updates.
Watching Slingbox on my desktop, installed updates to Windows 10, now Slingbox won't connect with either desktop or browser version.
Connects okay on my tablet. Rebooted Slingbox, computer and tried turning off firewall. Still not working. Slingbox player will still play commercials just not connect to the Slingbox itself.