I just bought 3 USB sticks from amazon. One 128GB PNY (very fast) and 2 Sandisk ultra fit (32GB and 128GB). The Sandisk 128GB has errors about 114GB in to 115GB total space. I consider replacing in with amazon, but wonder whether it is possible to download some Sandisk software to attempt to “repair” the defective device. I have never done this before, hence my question. I read about some overheating problems on this forum that might be the cause of fried cells in the flash. I don’t know anything about that, but it raises concern about the ability to keep the device stable for the 5 year warranty that you provide. I have been looking at downloadable software on your website for the repair, but could not find any. Could you please respond to whether it is possible to fix it or if I am better off returning it for a refund and get another brand or maybe even just a simple replace. The 4K speed of the 128GB one is half that of the 32GB one (read and write - 3½MB/s vs. 7MB/s and 2MB/s vs. 4MB/s). Useable storage of the Sandisk 128GB is 115GB. Useable storage of the PNY 128GB is 126GB. The size issue is of no concern, just bringing it up now that I had a problem. The speed issue however might be related to the flash error and do raise some red flags.