Maybe check the Freearc version and match the hash with Masquerade one.
Edit : Works for me too.
Code:
Compressed 1 file, 6,344,494 => 6,254,687 bytes. Ratio 98.58%
Compression time: cpu 0.02 sec/real 1.38 sec = 1%. Speed 4.59 mB/s
All OK
Code:
[External compressor:mpz]
header = 0
packcmd = mpzapi c <stdin> <stdout>
unpackcmd = mpzapi d <stdin> <stdout>