Just had a SanDisk Ultra A1 128GB card go into read only mode about 2 weeks ago. It's about 14 months old with less use than my SanDisk Ultra A1 256GB cards, which are still going strong in my A129 DUO setups. GUI Formatter pretends to format it, but all the files are still there after. Other programs just say there is an issue with the card and won't proceed. I'll send it to SanDisk and see if they will replace, even though it's loaded with dash camera files.