While attempting to set up permissons for users via PicketLink IDM, it is not possible to grant permission using File-based identity store.
Only JPA store (org.picketlink.idm.jpa.internal.JPAIdentityStore) implements grantPermission method. Neither LDAP nor file-based identity store supports permissions. Please either implement above-mentioned method in LDAP and File-based identity store or provide appropriate information in documentation.