We are having the same problem - additional data: If you switch to default dashboard the camera on that one is working - same camera same driverstation just the dashboard that looks like the driverstation. SmartDashboard was working on this driverstation prior to todays update I believe (not 100% positive) Still because the default dashboard works I don’t think its a firewall issue.
Ok - we fixed the problem on our driverstation. The driverstation doesn’t have the development environment on it so the wpilib tools directory never got updated with this years jar files. I copied my wpilib tools directory from my dev laptop to the driverstation and it seems much happier.
PS smartdashboard now has a mjpg camera and cameraserver options - cameraserver worked for us for this year