scp gives “not a regular file”

I just tested this and found at least 3 situations in which scp will return not a regular file:

1. File is actually a directory
2. File is a named pipe (a.k.a. FIFO)
3. File is a device file

Case #1 seems most likely. If you meant to transfer an entire directory structure with scp use the -r option to indicate recursive copy.