Use of clearcut

Hello, I am trying to use the clearcut command.
As the tutorial said, I run the dist.seqs comand first, generating the phylip formatted dist matrix.

mothur > dist.seqs(fasta=XXX.unique.fasta,cutoff=0.03,processors=2,output=lt); mothur > clearcut(phylip=XXX.unique.phylip.dist)

And the error is as follows:
Clearcut: Syntax error in distance matrix at offset 15.

I do not know much about clearcut, what I can do with this error?