1) First: I'm not an expert on StreamService... Do you have TCP networking disabled? Networking doesn't need to be on line, but I could understand a message if it was disabled. TCP is mainly used for connecting some particular flight sim games to LibrePilot so that LP can fly the sim in the sim's terrain. It is also used to send back some GCS stats over the internet if you opt in to sending some info the first time you run GCS. Does it connect to USB and do what you need? I would guess it doesn't hurt your functionality.
2) If you have a servo to test with, plug it in the receiver on that channel and see if the servo moves with the stick, or at least comes back to some position if manually moved with power off. I bought one of those radios for a friend long ago and finally traced a problem to this issue which I suggest you check out in the following link. In particular, watch the video (not my video, I just linked to it) to see just how badly it is affected:
https://www.rcgroups.com/forums/showthread.php?2145070-New-Flysky-FS-i6/page117#post38300831Oh yea one more thing. Certain plugging in with power on can fry an input or output. There are 3 pins on a servo connector and if the power and signal connect before the ground, then the signal is being used as a ground and is driven more negative than it should be (relative to the rest of the circuit). Always plug / unplug connectors with the power off. The good thing is that if that input is fried, you probably have a spare (most people only use 5 input channels). First, swap that broken channel (yaw) with one that is known to work (say roll) (receiver to CC3D wires). If the problem follows the CC3D input port and now causes the other function (roll) to fail, then you have a fried input port. Simply move the non-functioning channel to the unused input connector and re-run the transmitter setup wizard.