[Dr. Z]

Gopro recommends the following procedures. Note* if you do the reset procedure in step 2, you will have to reset the camera name and password but doing this may get back on the right path with WIFI connectivity.

HERO4 Session:

If the camera is unresponsive, you will need to reset the camera and re-enable Wi-Fi:

Part 1 - Reset the Camera:
Press and hold the shutter button for 8-10 seconds. Note: Resetting the camera does not reset the Wi-Fi

Part -2 Reset the Wi-Fi:

Press and hold the INFO/WI-FI button for 8-10 seconds; you will be prompted with "Reset Wi-Fi." The button can now be released.

Press the INFO/WI-FI button once to highlight YES.

Press the SHUTTER button once to select YES; the camera will prompt you that the reset has occurred, then turn off. Follow the pairing instructions here, to set up a new name and password during the GoPro App pairing process.

 

[Dr. Z]

Try what Kareem is suggesting first. It's possible you have some corrupted the firmware. Does it power on at all? No LED's lit or blinking? If they aren't, there could be a fault with the camera or your your charging method. It could also be a non-recommended GoPro of SD card (go to the Hero4 Session camera page of this forum and look for the sticky at the to for info), the SD Card must be formatted using FAT32 from the sd port on your computer prior to use in the camera. Or, there could be a loose connection somewhere inside the camera.

GoPro says to do the following:

1. Disconnect from any external power sources (i.e., not plugged in to anything) and remove the SD card.

2. Press the INFO/Wi-Fi Button to see if any information is displayed on the camera’s Status Screen.

3. If there is nothing displayed on the Status Screen, attempt to reset camera by holding the top SHUTTER button down for 8-10 seconds.

4. ​​If successful, the camera will advise you that the unit is "RESETTING." Normal operation should ensue after reset.

5. If still unable to get any response from camera, connect to a 5V 1A wall charger (ideally), or computer USB port; look for red LED illumination to indicate charging. NOTE: We do not recommend using a USB hub to charge the camera.
If/when red LED's illuminate, allow the camera to remain charging for a few minutes.

6. Disconnect the camera from charging source and attempt to turn camera on my pressing the top Shutter button (camera should read “NO SD CARD”).

7. If able to prompt NO SD message, allow camera to turn back off, insert SD card, and attempt to record a sample video.

If this procedure doesn't work you should contact gopro support for resolution to the problem. Let us know how it goes please.