Why is my SD card suddenly read-only? Is it dying?

Honestly, it sounds like your SD card is failing. When cards get into read-only mode, it's typically a sign that it's reached that threshold where it can't write anymore—kind of a fail-safe mode to protect your data.

Your issue sounds familiar. I had a Samsung Evo Plus 128GB card with the same problem. I could still see my files, but they were all in read-only mode, meaning I couldn't make any modifications. It usually happens when the card reaches its maximum read/write cycle count, which leads to that protective mechanism kicking in.

I transferred a bunch of files, including some that hadn't been touched in ages, to my phone storage. They opened fine, but when I tried moving them to a younger Sandisk 128 GB card, I still got the read-only error. My original files on the USB stick are perfect, not read-only at all. I'm starting to think it might be a problem with the Word app due to recent updates.

This issue has been popping up for a lot of users lately. Initially, we thought low-end or older cards were the problem, but there are newer, high-end cards facing this issue too, indicating it might be something else entirely. You might want to hang onto the card in case we figure out the root cause later. Some brands offer utilities that can check memory usage, but they're usually only for their own cards.

SD cards have a limited lifespan and unfortunately, when they begin to fail, they often go read-only. It's their way of trying to protect the data from being lost completely. You might need to consider replacing it soon.