Squirrelmail importer plugin not working

[lgp171188]

I have a squirrelmail webmail configured and I am now migrating to roundcube. I have configured the squirrelmail importer that comes with roundcube. I have given the database settings of squirrelmail database and also the path to the squirrelmail data directory. When the user logs into the roundcube interface for the first time, I notice that the addressbook is not imported. How to debug further and see what is wrong?