I been there with the flash drive write-lockout issue and there is a non-techie preventative.
The problems many are having in installing Mint or other excellent Linux or Windows OSes on flash drives can largely be averted by installing OSes that wholly reside in RAM such as Porteus and Puppy. They are highly forgiving of being unplugged or plugged to your PC without warning and have the intrinsic added benefit of greatly expanding the lifetime of your drive with way less wear and tear on the cells and under USB 3.0 runs much much cooler too. I installed Porteus 3.1 on my new Ultra Fit 32gig mini WITHOUT reformatting it (and inviting problems seeded by that processs) via Porteus’ .Dat container feature and Linux runs like a dream on a safely factory-formatted FAT drive. Even does Wine super well.
I encourage all to test out RAM-resident OSes if you plan on running a live OS on your flash,
Jim in NYC