Hi @felipe.borrero,
Is DROPFOLDER_PLUGIN_PERMISSION enabled for the partner?
To verify, go to Admin Console->Publishers->Your Partner->Actions->Configure and ensure the Content Ingestion - Drop Folder/s checkbox is checked.
Assuming that it is, if it still doesn’t work then check for errors in /opt/kaltura/log/kaltura_api_v3.log as well as in /opt/kaltura/log/batch/dropfolder*.log
Once you’ve got the relevant log lines, post them here and I’ll have a look.