Can't connect to one folder

I'm using Filezilla with SmartFTP. I have three folders that I am trying to connect to. Two of them I can connect and see files easily. The third folder has many many files and I get the following error when I try to connect to that folder:


150 Opening data channel for directory list.
Transfer Timeout (40s). Closing data connection.
36500 bytes transferred. (916 bytes/s) (00:00:39)
426 Connection closed; transfer aborted.


All folders have the same share premissions for my users.

What's going on with this particular folder?