RonJacobi Glad to hear you were able to recover the photos. Yes, now that recovery is complete, it’s safe to format the SD card. To keep things simple and compatible, I recommend inserting the card into the camera you plan to use it with. Then format it from the camera’s menu. Most cameras will format the card properly (usually to FAT32 or exFAT).
In my opinion, that's the best option (tends to result in fewer issues later). If you prefer to format on your PC, that works too. Use exFAT or FAT32. Either way you should be good to go.
Edit: One more thing, it might be worth running a quick scan with Victoria (or a similar tool) to check for bad blocks. Also, some high-end cards even show S.M.A.R.T. data, which can give you a heads-up if the card is starting to fail. If bad blocks have started to appear, I wouldn’t keep using it. The same issue could happen again, and the next time you might not be so lucky.
