Yeah, I've got two of those in a drawer right now. Wont format, and that right out of the package. I would send em back, but that seems like a lot of trouble, and they weren't ordered from amazon, got em from Wish, and they ship from Shengen China, so I have two tiny paperweights..LOLNobody here has said to watch out for knock offs that look very real. Check out YouTube first on how to identify the difference between the real ones and the fakes. Then buy your memory from a reputable store. I own a P34K and I have had good luck with SanDisk Extreme 64gb C10 U1 class memory but I get the one that has U3 on it because its faster. For good 4K without shudder even when doing fast turns etc this is the one to buy. You want to be interested most in write speed a minimum of 40mbs is recommended and will deliver good results.