Suddenly, my 32gb Sandisk USB key stopped working on my Macbook. I plugged it in and it was not seen my the Macbook. It didn’t appear under the System Profiler, in Disk Utility nor in the terminal. After some struggling, I was able to make it work again.
Hot to fix the Usb drive not seen by Mac problem
The drive was still working with other PCs, so it was definitely a Mac issue. I tried to reset the Mac SMC and to reset the NVRAM / PRAM, with no luck. Then, I found this solution.
It your Usb drive is not seen by your Macbook, open Terminal and run the following commands:
sudo rm -r /System/Library/Extensions/SATSMARTDriver.kext
sudo rm -r /System/Library/Extensions/SATSMARTLib.plugin
Reboot your Mac and the problem could be gone!