I got one off ebay that says it will work in phones (just MicroSD 128gb, no brand on anything, the package even just had a foldover piece of plastic on the front. I'm guessing, since the seller is in the US, he just bought a generic lot and gambled he could sell them fast. That makes me want to push it around the block as hard as I can, as rapidly as I can so I can return it if need be. I bet he won't be on ebay in a few weeks, but since he is now, ebay can wield a pretty fierce club on sellers who sell non-working junk. The seller says it is Fat32 formatted.
Anyway I put it in my wifi 12.2 and it shows up as 125gb free, but I can't put anything on it through the device (PC over USB 3.0 can see the card but won't transfer files or make a folder; I can't create a folder via Zarchiver or ES File Explorer), but some programs have written to it (firefox, google, flipboard... but can't save to it firefox and quickpic can't save there). I'm NOT rooted (so no fix).
I'm trying to figure out if it is the generic nature of the card, or if it is just that I don't have root yet and have not applied the fix. If it were a 64gb card I would not be too worried (I would think it is the kitkat issue), but it is the 128gb card so I don't know. An OP has said that they had problems with generic 64gb cards being fake (I admit I have not done the research on fake micro sd cards), so this makes me worry a bit.
I just want to make sure that the card works so I don't have to return it. I'll try out a new 32gb card I have tonight and I'll try it in the adapter just with my PC to see if I can read from it on the 12.2 tonight, then I guess I'll root (Yea LMT!!!).
I'm open to any suggestions you might have for me.