memory card file name changed-not able to get into file

I took some pictures on a memory card I have used mulitiple times in the past. When I put it in my card reader to edit the pictures, I am receiving this message:

File name, directory name or volume label syntax is incorrect…   The file name changed to USBC0Z+  somehow. My camera always uses a file similar to 101MSDCF which always lets me open the pictures. The memory card I am using is a Sandisk SDHC 4 16GB. There are some sentimenal pictures on here of my son when he was little and I simply can’t lose them. Any help would be greatly appreciated!!