I see from your screen capture that the firmware you have loaded is 15.02.02. You must use OpenPilot 15.02.02 GCS to talk to that. You can't mix different versions of GCS and firmware. If your only problem is that you have mixed versions then all you need to do is install a matching firmware using the Manual "Upgrade and Erase" method on this page:
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/5669026/Firmware+Tab#FirmwareTab-ManualmethodOr you could find an OpenPilot 15.02.02 GCS download and use that.
If that doesn't fix it...
What does the LED do? Slow fade on and off or normal blinking or something else?
Where does the "Manual Method" "Upgrade and Erase" fail?
If that doesn't work, then try this with matching versions of firmware and GCS:
- unplug board
- press Firmware->Rescue button
- it will tell you to plug the board in to USB, so plug it in
- press Firmware->SafeBoot button
if that works, then you just have configured something wrong, like moved telemetry off of USB onto MainPort, so it isn't talking to you normally. Doing a Rescue with EraseSettings might fix it. Of course be aware that you will loose your settings if you do this. If that is important, ask about it.