RAW files not opening

[teamk63193216]

I've been uploading my RAW files into my Photoshop Elements 12 for month now with no problem.  Today I went to edit some of my artwork for a job portfolio and it wouldn't recognize my RAW files.  Are my files corrupted?  And is there anything I can do?  I no longer have all original art that I photographed so I'm kind of freaking out.  I've tried other nef to jpg apps just to make sure and they don't recognize them either. Any insights would be super helpful!

[John Waller]

Need more info.

Raw files from which camera make and model?

How do you get the Raw files out of the camera? Camera to computer? Card reader?