Convert Autodesk FLI to au

Download and install the latest version of Filestar.
Right click on one or more Fli file(s) on your desktop and select Convert with Filestar.
Type convert to au in the search box.
Press Convert.

What is the difference between Autodesk FLI and .au?

Name: Autodesk FLI; Audacity Audio File
Extension: .fli; .au
Format: Binary; Binary
Category: Raster Image; Audio
Developer: Autodesk; Audacity
Description: Audio file created by Audacity, a free, cross platform audio editor; uses a proprietary format that can only be opened by Audacity; saved as one of multiple audio data files for an Audacity project (.AUD).
MIME Type: audio/basic
Sample: sample.au
Wikipedia: .au on Wikipedia