CD Ripper has started to drop file extensions on my computer. Instead of a file extension like ".flac," I am getting file names that end in "._"

After a computer reboot, on the first disk ripped all filenames have the flac extension, the second disk had five files with ._ instead of the file extension. The files with the missing file extension were in no particular order, nor in sequence (tracks, 5, 15, 18, 20, 21 were missing the flac extension). The third disk I ripped had no file extensions at all.

The files are all ripped properly. If I change the ._ to .flac, the files play and sound perfect. Accurate Rip reports back that the files are OK.

It has nothing to do with the length of the file name. Both long and short file names are affected.

Does anybody have any idea how to fix this.

Thanks for the help

Roger