It seems that you are having some issues with your Slingbox SOLO since you are not able to update the firmware version and you get no video signal.
If you have the Slingbox SOLO and it is running under the 1.3.16 firmware version, you must update it to the latest version which is 2.1.120. If you do not know how to or have some issues trying to update the firmware version, make sure to check this link and follow the included steps:
Regarding the video issue, I recommend you to check if you are using the HDMI cable between the TV set and the PVR. If you are, you must remove it since it is not compatible with any Slingbox model due to the High-bandwidth Digital Content Protection (HDCP) restriction. The following links will provide you with the explanation and a possible workaround:
Finally, I recommend you to check this link in order to know the supported Operating System and web browser versions (this could be the root cause for the plug-in installation issue):