Interestingly I got some new bins using this serial modifier that came out, and they worked right out of the box without having to rename them to an accepted file. Several of them briefly said 'failed' when copying, but worked anyway (which happens once in a while as it is). I'm pretty sure the original failure problem was legit though because it STAYED on "Failed" and didn't immediately successfully scan
The serial modifier thing is neat because it means you can use multiples of the same one in a day, but the unfortunate thing is you still have go to to the trouble of changing your powertag that many times. I'm actually happy doing 15 of them a day, but 20 is really starting to push it.
I wonder what would happen if you had two of the wolf... well now i'm getting more off-topic
point is, everyone who's having trouble with the process, ignore all that stuff about .exes and just get a powersaves and put bins on the powertag. You don't need to do anything else except once you have enough money actually buy some amiibos to keep it honest.....
P.S. apparently some powertags are burning out/bricking after 50-100 uses (mine's already well past that), and the current theory is that it involves moving the tag off of the reader while it's trying to write, so for god's sake put your reader somewhere stable and don't touch the tag while it's writing.