I bought two sandisk ultra 64gb and 32gb from a e-commerce site in august 2017 for my visit to south india. the 32gb was working effectivelytill now, but the 64gb memory card created problem after the purchase of 10 days.
It is of class 10 even then it makes a hang situation like a class 2 or 3 card. I also lost some data while putting it to another device. I format this and reuse, it works good for some days and again this time also the problem remains same.