PGP Command Line: Encrypt Error :3064 Invalid Key

Hi Team,

I'm encripting a file with a shared public key, but when I encrypt I have Error 3064 Key Invalid.

C:\pgp --encrypt testFile.txt --recipient 0xB9548AA8
0xB9548AA8:encrypt (3064:key invalid)
testFile.txt:encrypt (0:output file testFile.txt.pgp)

So, the file is encrypted but that error is displaying, Why is showing the error?