(3/30/2017) - Firefox has stopped supporting Java with their latest release, Firefox Version 52. To continue using the Advanced Uploader with Firefox, you have 2 options:
1) Download the Extendable Support Release (ESR) to enable Firefox 52 to support the Java plugin*.
*Note: For Windows users, use the the 32-bit Firefox ESR browser. 64-bit will NOT WORK.
2) Rollback to Firefox Ver. 51
You can also use IE (Windows) or Safari (Mac) browsers for the Advanced Uploader.
To use the Advanced Uploader tool within a Firefox browser:
1) Click on the Advanced Uploader icon in your Profile menu
2) A new tab will open. Click "Allow" for Firefox to run the Java-based tool.
3) Select "Allow and Remember" in the upper-left corner.
4) Click "Run" when prompted to run the application.
5) A new window will open. Click "Upload to" to select which Flight folder to upload to.
6) Click "Select a folder on your local drive" to select your local folders to be uploaded*.
7) Click "Upload" to upload your local folders to Flight.
*The folder structure you select will be retained in Flight.