Audacity FFMPG exporting partial file

Question

New Problem Audacity with new FFMPEG, Export 8 channels to 7.1 and it cuts out at 23 minutes. its 2 hour long tracks. It goes to 1.x near the end, plenty of disk space, not sure what is wrong with it.

ffmpeg -i - -strict experimental -c:a aac -b:a 240k "F:\Something.aac"

ffmpeg version N-82966-g6993bb4 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.0 (GCC)
  configuration: --disable-static --enable-shared --enable-gpl --enable-version3 --enable-dxva2 --enable-libmfx --enable-nvenc --enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enable-iconv --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenh264 --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxavs --enable-libxvid --enable-libzimg --enable-lzma --enable-decklink --enable-zlib
  libavutil      55. 43.100 / 55. 43.100
  libavcodec     57. 70.100 / 57. 70.100
  libavformat    57. 61.100 / 57. 61.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 68.100 /  6. 68.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
  libpostproc    54.  2.100 / 54.  2.100
Guessed Channel Layout for Input Stream #0.0 : 7.1
Input #0, wav, from 'pipe:':
  Duration: N/A, bitrate: 5644 kb/s
    Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 44100 Hz, 7.1, s16, 5644 kb/s
Output #0, adts, to 'F:\Something.aac':
  Metadata:
    encoder         : Lavf57.61.100
    Stream #0:0: Audio: aac (LC), 44100 Hz, 7.1, fltp, 240 kb/s
    Metadata:
      encoder         : Lavc57.70.100 aac
Stream mapping:
  Stream #0:0 -> #0:0 (pcm_s16le (native) -> aac (native))
size=      63kB time=00:00:02.18 bitrate= 237.6kbits/s speed= 4.3x    
size=     117kB time=00:00:03.99 bitrate= 240.0kbits/s speed=3.96x    
size=     145kB time=00:00:04.94 bitrate= 240.3kbits/s speed= 2.4x    
size=     193kB time=00:00:06.57 bitrate= 240.8kbits/s speed=2.57x    
size=     249kB time=00:00:08.45 bitrate= 241.1kbits/s speed=2.76x    
size=     293kB time=00:00:09.96 bitrate= 241.3kbits/s speed=2.45x    
size=     353kB time=00:00:11.98 bitrate= 241.5kbits/s speed=2.62x    
size=     386kB time=00:00:13.09 bitrate= 241.6kbits/s speed=2.58x    
size=     441kB time=00:00:14.95 bitrate= 241.7kbits/s speed=2.42x    
size=     506kB time=00:00:17.13 bitrate= 241.7kbits/s speed=2.57x    
size=     575kB time=00:00:19.48 bitrate= 241.8kbits/s speed=2.72x    
size=     589kB time=00:00:19.94 bitrate= 241.9kbits/s speed=2.53x    
size=     655kB time=00:00:22.17 bitrate= 241.9kbits/s speed=2.65x    
size=     736kB time=00:00:24.91 bitrate= 241.9kbits/s speed=2.81x    
size=     737kB time=00:00:24.96 bitrate= 241.9kbits/s speed=2.63x    
size=     809kB time=00:00:27.39 bitrate= 242.0kbits/s speed=2.74x    
size=     885kB time=00:00:29.95 bitrate= 242.0kbits/s speed=2.71x    
size=   31922kB time=00:17:56.36 bitrate= 243.0kbits/s speed=3.15x    
size=   31991kB time=00:17:58.70 bitrate= 243.0kbits/s speed=3.15x    
size=   32029kB time=00:17:59.96 bitrate= 243.0kbits/s speed=3.14x    
size=   32053kB time=00:18:00.77 bitrate= 243.0kbits/s speed=3.14x    
size=   32084kB time=00:18:01.84 bitrate= 243.0kbits/s speed=3.14x    
size=   32116kB time=00:18:02.88 bitrate= 243.0kbits/s speed=3.14x    
size=   32144kB time=00:18:03.83 bitrate= 243.0kbits/s speed=3.14x    
size=   32177kB time=00:18:04.95 bitrate= 243.0kbits/s speed=3.13x    
size=   32248kB time=00:18:07.34 bitrate= 243.0kbits/s speed=3.13x    
.... Repeat of much of the same 3.0x throughout
size=   40419kB time=00:22:42.89 bitrate= 242.9kbits/s speed=3.03x    
size=   40449kB time=00:22:43.91 bitrate= 242.9kbits/s speed=3.03x    
size=   40480kB time=00:22:44.96 bitrate= 242.9kbits/s speed=3.03x    
size=   40557kB time=00:22:47.56 bitrate= 242.9kbits/s speed=3.03x    
size=   40628kB time=00:22:49.95 bitrate= 242.9kbits/s speed=3.03x    
size=   40719kB time=00:22:53.01 bitrate= 242.9kbits/s speed=3.03x    
size=   40751kB time=00:22:54.11 bitrate= 242.9kbits/s speed=1.06x    
size=   40753kB time=00:22:54.15 bitrate= 242.9kbits/s speed=1.06x    
video:0kB audio:40348kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.002666%
[aac @ 00000000026d5aa0] Qavg: 331.324

Answer 1

Full output, included some errors, but ended up working perfectly once joined back to MKV. I exported each track from audacity as a seperate file, and then used ffmpg to join them using the following options

F:\unsorted\Jurassic World 2015 (1080p Bluray x265 HEVC 10bit AAC 7.1 Tigole)\Mult>"C:\Program Files (x86)\FFmpeg for Audacity\ffmpeg" 
-i F:\Something-audio 1.aac" -i F:\Something-audio 2.aac" -i F:\Something-audio 3.aac" -i F:\Something-audio 4.aac" -i F:\Something-audio 5.aac" -i F:\Something-audio 6.aac" -i F:\Something-audio 7.aac" -i F:\Something-audio 8.aac" 
-filter_complex "[0:a][1:a][2:a][3:a][4:a][5:a][6:a][7:a]amerge=inputs=8[aout]" -map "[aout]" -c:a aac F:\Something-Merged.aac"


ffmpeg version N-82966-g6993bb4 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.0 (GCC)
[aac @ 0000000003b2c220] Estimating duration from bitrate, this may be inaccurate
Input #0, aac, from 'F:\Something-audio 1.aac':
  Duration: 11:00:40.97, bitrate: 39 kb/s
    Stream #0:0: Audio: aac (LC), 44100 Hz, mono, fltp, 39 kb/s
[aac @ 00000000020b8e80] Estimating duration from bitrate, this may be inaccurate
Input #1, aac, from 'F:\Something-audio 2.aac':
  Duration: 10:21:45.38, bitrate: 42 kb/s
    Stream #1:0: Audio: aac (LC), 44100 Hz, mono, fltp, 42 kb/s
[aac @ 0000000003b340c0] Estimating duration from bitrate, this may be inaccurate
Input #2, aac, from 'F:\Something-audio 3.aac':
  Duration: 01:55:51.11, bitrate: 249 kb/s
    Stream #2:0: Audio: aac (LC), 44100 Hz, mono, fltp, 249 kb/s
[aac @ 0000000003b54740] Estimating duration from bitrate, this may be inaccurate
Input #3, aac, from 'F:\Something-audio 4.aac':
  Duration: 03:19:22.33, bitrate: 38 kb/s
    Stream #3:0: Audio: aac (LC), 44100 Hz, mono, fltp, 38 kb/s
[aac @ 00000000020bbf60] Estimating duration from bitrate, this may be inaccurate
Input #4, aac, from 'F:\Something-audio 5.aac':
  Duration: 09:30:06.73, bitrate: 38 kb/s
    Stream #4:0: Audio: aac (LC), 44100 Hz, mono, fltp, 38 kb/s
[aac @ 00000000020bcec0] Estimating duration from bitrate, this may be inaccurate
Input #5, aac, from 'F:\Something-audio 6.aac':
  Duration: 09:14:32.01, bitrate: 39 kb/s
    Stream #5:0: Audio: aac (LC), 44100 Hz, mono, fltp, 39 kb/s
[aac @ 0000000003b8dc00] Estimating duration from bitrate, this may be inaccurate
Input #6, aac, from 'F:\Something-audio 7.aac':
  Duration: 09:32:02.44, bitrate: 39 kb/s
    Stream #6:0: Audio: aac (LC), 44100 Hz, mono, fltp, 39 kb/s
[aac @ 0000000003bb7220] Estimating duration from bitrate, this may be inaccurate
Input #7, aac, from 'F:\Something-audio 8.aac':
  Duration: 09:37:28.19, bitrate: 39 kb/s
    Stream #7:0: Audio: aac (LC), 44100 Hz, mono, fltp, 39 kb/s
[Parsed_amerge_0 @ 0000000003cc02e0] No channel layout for input 1
[Parsed_amerge_0 @ 0000000003cc02e0] Input channel layouts overlap: output layout will be determined by the number of distinct input channels
Output #0, adts, to 'F:\Something-Merged.aac':
  Metadata:
    encoder         : Lavf57.61.100
    Stream #0:0: Audio: aac (LC), 44100 Hz, 7.1, fltp, 469 kb/s (default)
    Metadata:
      encoder         : Lavc57.70.100 aac
Stream mapping:
  Stream #0:0 (aac) -> amerge:in0
  Stream #1:0 (aac) -> amerge:in1
  Stream #2:0 (aac) -> amerge:in2
  Stream #3:0 (aac) -> amerge:in3
  Stream #4:0 (aac) -> amerge:in4
  Stream #5:0 (aac) -> amerge:in5
  Stream #6:0 (aac) -> amerge:in6
  Stream #7:0 (aac) -> amerge:in7
  amerge -> Stream #0:0 (aac)
Press [q] to stop, [?] for help
[aac @ 0000000003b40840] TYPE_FIL: Input buffer exhausted before END element found
Error while decoding stream #6:0: Invalid data found when processing input
[aac @ 0000000003b40840] error in spectral data, ESC overflow4.85x
Error while decoding stream #6:0: Invalid data found when processing input
[aac @ 0000000003b46940] channel element 0.15 is not allocated.78x
Error while decoding stream #1:0: Invalid data found when processing input
[aac @ 0000000003b46940] Input buffer exhausted before END element found
Error while decoding stream #1:0: Invalid data found when processing input
[aac @ 0000000003b92c20] noise_facs_q 31 is invalids/s speed= 4.4x
[aac @ 0000000003b92c20] Sample rate index in program config element does not match the sample rate index configured by the container.
[aac @ 0000000003b92c20] decode_pce: Input buffer exhausted before END element found
Error while decoding stream #4:0: Operation not permitted
size=  429971kB time=02:04:21.10 bitrate= 472.1kbits/s speed=4.45x
video:0kB audio:427775kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.513483%
[aac @ 0000000003b411e0] Qavg: 668.628