I am trying to run the walkmod pmd plugin but getting “The chain pmd is not found”.

Below is the walkmod.xml:

<!DOCTYPE walkmod PUBLIC “-//WALKMOD//DTD” “http://www.walkmod.com/dtd/walkmod-1.1.dtd">
<walkmod>
<transformation type=”imports-cleaner”/>
<transformation type=”pmd”/>
</walkmod>

I am using the below command for apply pmd:

walkmod apply -DconfigurationFile=ruleset.xml pmd
Can you please help me if i am missing something.