What happened to my microSD card???

[AC Question]

I recently attempted to take a couple of pictures with my Samsung Galaxy S5. I have done so many times in the past, within the last 24 hours in fact. But this time when I opened the default photo gallery on the phone to view the pictures, they showed up as just a blank grey image. First, i removed the card and put it back in, then I tried to restart the phone, but it was working very slowly. I took the battery out and replaced it, and booted up the phone. Everything seemed to work fine, until I attempted to open up the photo gallery again. It took multiple attempts to get the application to open, and when I finally got it to open, all photo albums that had been stored on the card had disappeared. I looked at all my applications, and the ones that were installed on the card said "Application not Installed" when I tried to open them, as well they had grayed out logos. I opened up the file manager that comes on the phone, and the card was listed in storage devices, under the phones local storage. When I tapped on it to view the files, there were no contents on the card. I plugged the phone into my computer to see if I could access the card via the computer, but it is not listed in the storage locations on my phone. What I would like to know is, did I do something wrong? And if I did, can I restore the files that were on the card if I put it directly into the computer?

 

[ManiacJoe]

Which phone?
Which version of android?
Which carrier?

Was the SD card formatted as external storage or adoptable/internal storage?