This problem can usually be fixed by wiping the SD card of all its files. This will get rid of any "ghost" files that may be taking up storage space or causing issues with the GoPro. For more answers visit the GoPro Hero 3+ troubleshooting page: GoPro Hero3+ Black Edition Troubleshooting

This is a common problem and generally requires you to reset the GoPro. You must first remove the battery and the SD card from the device. Then, replace the battery and hold the shutter button. If the GoPro turns on, power back off and insert the SD card. You may need to reformat the SD card again using the GoPro before using it again. For more answers visit the GoPro Hero 3+ troubleshooting page: GoPro Hero3+ Black Edition Troubleshooting

This may be as simple as the GoPro doesn't have enough charge. When charging ensure that the display is off and that the red light on the front is solid. Leave it to charge for a few hours and it should be fine. For more answers visit the GoPro Hero 3+ troubleshooting page: GoPro Hero3+ Black Edition Troubleshooting