des3 decrypt bad magic number

[barchia]

Hi to *

I try to decode a  file that is encripted with  des3  cipher, 
the file is encoded with .NET framework, the key is 128 bit


when i type the openssl command:

C:\test\des3>openssl des3 -d -in fileencodec.enc -out fileout.txt -K 7e46960de0c59530f7332b3eedb5867e -p
    -iv "0000000000000000" -p
salt=78013E0001000000
key=7E46960DE0C59530F7332B3EEDB5867E0000000000000000
iv =0000000000000000
bad decrypt
948:error:06065064:digital envelope routines:EVP_DecryptFinal:bad decrypt:.\crypto\evp\evp_enc.c:509:

why I have "0000000000000000" at the end of key?
what mean?

or:

C:\test\des3>openssl des3 -d -in PI_FATT_0606_0017_03226_114108.enc -out file.txt -pass file:key.decrypted  -iv "0000000000000000" -p
bad magic number

If decode all with C# in .NET all work fine...

where is the mistake?

Thank in advance... 

Alessandro B.