To be honest it's probably a lost cause to try to get those corrupted files back. If I were you I'd just get it into a computer and save whatever else I can, then format the card in the phone. In fact I did exactly that after reading your post, just in case.
I just transferred everything I could to internal storage on the phone. I'm obviously unhappy about losing some of those files but more concerned about what happens in the future. Will the same thing happen to additional files when I upgrade the phone the next time? Will i be able to use expandable memory or am I going to have to save everything to internal storage.
You can use a memory card, it is recommended to format a card everytime you insert it into a new phone though, I forgot where I saw it, but now I remember seeing it stated somewhere.
I am experiencing the same proble with pictures. I had a S7 Edge and moved the 64Gb Card to a Note 9. Just unplugged the SD card and moved it. All looked well and then over the next several days I noticed I was missing some pictures. Since then I have noticed I have A LOT of corrupted pictures.
I purchased a 256Gb Card formatted and installed it and then copied over my pictures from the 64Gb SD Card. Have LOTS of corrupted pictures. Over time it appears like more and more pictures are becoming corrupted.
Any advice would help.
I recommend contacting our Memory Support Team for further troubleshooting. Please either email email@example.com or call 1-800-Samsung and choose option 7 for SD support. The SD support team is available M-F 9 AM - 9 PM. Also, for best performance be sure to always use a class 10 or higher SD card with your Galaxy Note 9. Older SD cards may not work as well with a newer flagship device. Older model SD cards can cause freezes, malfunctions, and it can cause your phone to reboot.
If the photos/files are that valuable to you, why haven't you backed them up, copied them off somewhere, and are entrusting them to be stored on a device that could be stolen, get lost, or get damaged in such a way that somehow the microSD card (which isn't the most stable media to begin with) fails to operate?
I have owned several phones by Samsung and this is my second Note (never had a corruption issue such as this - knocking on melamine covered particle board). I always handle the microSD card myself as I would never trust a store clerk to handle moving the contents of my wallet to a new wallet. Here's the steps I take (probably means nothing to you now):
1. Remove microSD card from old phone, copy all content I want to save (especially photos). Leave microSD card at home so as I don't lose it.
2. Take phone in for promotion or just go buy the new phone.
3. Put in microSD once I get the new phone home, format it, copy photos/videos to new phone now since I know the microSD should be stable and I have the backup on my computer regardless.