You may try ejecting and re-inserting the card. If that doesn't solve the problem, perhaps the following thoughts may be helpful:
Do you have a card reader capability on your computer? If so, you could try reading the card this way. That might determine whether the card is corrupted.
A number of folks have had issues with SD card corruption. Replacement has typically been the fix. Fortunately SD cards are inexpensive. Setting up a replacement card isn't difficult.
I tried removing then reinserting the card and that didn't do anything. I turned it on this morning and noticed that it now gives me an "SD Card File Error".
As for the card reader capability, I can read a standard size SD card, but not Micro SD.
There was an incident that I had a few weeks ago. I turned on the scanner and it froze in the "Loading Database" phase. It wouldn't even turn off. I ended up having to disconnect the AC adapter and then plug it back in again. After that, it was fine.
I don't know if this is significant or not, but I have had that scanner for almost exactly one year now.