If your file is in the "Uploads" folder, it has not been processed. Normally a file will be picked up for processing within 15 minutes.
It must be noted that if the file stays in the upload folder, most likely the file extension is not CSV. All files uploaded to the SFTP site must be in the CSV file format.
For all other errors that occur during processing, a membership response file will be generated with the specific errors.
This file will be placed in the "done" folder, under a subfolder called "Membership Response".
You can see specific information regarding the Response file Here