GoPro HERO3 Silver will no longer mount

Thanks for your help! Yes, I can insert the micro SD card into the SDXC slot using an adapter, and it reads just fine (i.e., I can download media off the card). If there is no other solution, at least I have this option.

The issue is that the GoPro used to mount just fine using a USB cable, and I didn't have to bother with taking the memory card out and putting it into an adapter every time I wanted to download media onto my computer. Once I changed the memory card, the GoPro won't mount directly. I changed back to the old card to see if that was the issue, but even with the old card, the GoPro won't mount directly anymore–I have to use the SD slot. So, it's not like the overall function is compromised, but it's a pain in the butt and frankly, if it worked once, I don't understand why it won't mount again. I thought I'd turn to the community to see if someone had a fix.

Formatting the card in the GoPro is a good suggestion, which is why I tried it ;-). The very first thing I did was format the SD card in the GoPro, and it wouldn't mount. Then, I took the SD card out and used my Macbook Pro to reformat it (FAT is required), loaded the folder setup from the previous SD card, put it back in the camera, and success! The GoPro mounted. Then I unmounted it, took a sample video (it recorded with no problems), and then tried to remount it. No luck. I took the card out, used the adapter and mounted it directly through the SDXC slot, and I could download the sample video. I left the video on the card, unmounted the SD, put it back in the GoPro, and tried to mount it directly using the USB cable. No luck. So, I can get my videos off the memory card, but I can't do it directly from the GoPro like I could in those happy, innocent days (earlier in the week).

So, apart from the real issue of me being lazy, the computer is being 'inconsistent' in recognizing this external device. I imagine that the issue could be with the GoPro, but because it mounted once (and used to mount regularly), I'm thinking there's something else going on... especially because even the old micro SD card won't mount in the GoPro anymore. If at all possible I'd like to not have to take out the memory card every time I want to download off the camera.

Thanks for the suggestion! I tried that... to no avail. However, after a weekend-long bike trip where I shot about 6 hours of footage at high resolution, I used the "take-the-card-out" method and found that the photo import took less than half the time it used to take just using the camera/USB method. So, all-in-all I think I now prefer the memory card option, even if I'm scared poopless that the fragile little Micro-SD card with break (probably sticking half-way out of the camera).

Update: after updating the firmware and using the card reader method (i.e., taking it out) a few times, I tried plugging in the camera on a whim and success! It seemed to mount just fine. I personally think that there was some update Apple did to iPhotos that made it work. Whatever they fixed, it was great...

BUT, since the OS X 10.10.3 update, I can't even get the GoPro to recognize it's plugged in to the computer. It won't even charge (but it still charges when plugged into a USB wall outlet and in my car USB charger). Not sure if it was OSX10.10.3 that did it (or just the move to Photos). Either way, lame.

Well, if you're having this problem, I would suggest you do it this way:

Take the microSD memory card out of the camera, put it into a regular SD adapter card, and mount just the memory card directly using the SD slot. Then download the firmware update from GoPro's website and save it to the memory card (it might be several executable files, but I'm not sure of what the file extension is). When done, safely eject the memory card, take it out of the adapter, and put it back in the camera. Turn the camera on, and it will automatically install the update. Fair warning, the camera can take a little while updating.

If you're asking how I (explicitly) did it, it involved more intermediate steps like "get beer from fridge", "answer phonecall", and "cuss at the camera for not installing the update the first time". But, these steps should work for you.