The most common problems are that the tlk gets extracted into the hak folder and/or the haks get extracted into a subfolder.
1. Open your NWN/hak folder
2. Make sure there are no subfolders.
a. If there are subfolders, move the hak files into the NWN/hak directory
3. Make sure the tlk file is in the NWN/tlk folder
You should be good to go after that.