Fairuse 2.8 (Full Edition) abortes processing a job with the log message below:

23:59:55 3320 -----------------------------------------------------
23:59:55 3320 Will create final file with following command line
23:59:55 3320 "C:Program FilesFairUse Wizard 2mp4box.exe" -nodrop  -fps 25 -add "C:   mpdvdWhite.session-01.video-stream.0.264#video" -add "C:   mpdvdWhite.session-01.audio-00.aac.aac" -new "C:   mpdvdWhite.session-01.mp4"
00:00:18 3320 File "C:   mpdvdWhite.session-01.mp4" not found!
00:00:18 3320 -----------------------------------------------------
00:00:18 3320 _OutputProcess() : Muxing failed (aborting)
00:00:18 3320 _TranscodeProcess() : Muxing failed!

To provide some useful information to track down the bug - the problem is obviously caused by the wrong filename "White.session-01.audio-00.aac.aac". This audio file was created correctly as logged below:

10:55:24 3320 ffmpeg.exe -y -i "C:   mpdvdWhite.session-01.audio-00.wav" -acodec libfaac -ab 96k "C:   mpdvdWhite.session-01.audio-00.aac"

That means there was never a file created with twice the extension "aac". Fairuse 2.8 inaccurately appended this file extension again.

Moreover the whole processing seems not very accurate since the movie was actually requested to get two audio stream (which were both created before). The final command line instead suggest me that the movie would get only one of the requested audio streams.