[tebasuna51]

1) Please verify than you use:
Options -> Settings -> Extra Configuration -> Auto Update -> Use Development Update Server

2) And update your soft
Options -> Update

Because:

--[Information] [29/08/2016 07:51:41 p.m.] Automatic update is disabled
--[Information] [29/08/2016 07:51:41 p.m.] Using cached update config and server: http://megui.org/auto/stable/
--[Information] [29/08/2016 07:51:42 p.m.] There are 8 packages which can be updated: MeGUI, MeGUI Libraries, MediaInfo, x264, x265, MP4Box, FFMS, L-SMASH Works

Now your audio stream can be decoded only with DirectShowSource:

--[Information] [29/08/2016 07:55:52 p.m.] Trying to open the file with LWLibavAudioSource()
--[Information] [29/08/2016 07:55:53 p.m.] Failed opening the file with LWLibavAudioSource(). LWLibavAudioSource: failed to get the audio track.
--[Information] [29/08/2016 07:55:55 p.m.] Trying to open the file with FFAudioSource()
--[Information] [29/08/2016 07:57:59 p.m.] Failed opening the file with FFAudioSource(). FFAudioSource: Failed to open 'C:\MOVIE.mkv.ffindex'
--[Information] [29/08/2016 07:57:59 p.m.] Trying to open the file with DirectShowSource()
--[Information] [29/08/2016 07:58:04 p.m.] Successfully opened the file with DirectShowSource()
--[Information] [29/08/2016 07:58:04 p.m.] Avisynth script
---[NoImage] LoadPlugin("C:\Program Files (x86)\MeGUI_2507_x86\tools\avs\plugins\directshowsource.dll")
---[NoImage] DirectShowSource("C:\MOVIE.mkv", video=false)

And we don't know if the audio is decoded properly or not.

3) BTW, now the MediaInfo of your audio is coherent:

---[Information] Audio
----[Information] FormatProfile: HE-AAC / LC
----[Information] FormatSettingsSBR: Yes (Implicit)
----[Information] SamplingRateString: 48.0 kHz / 24.0 kHz
----[Information] Channels: 6
----[Information] ChannelPositionsString2: 3/2/0.1

If your audio is still with low volume try after update MeGUI, until the file can be oppened by LWLibavAudioSource().

4) There are also other recomendations to avoid problems with folders protected by Windows:

a) Don't install portable soft, like MeGUI, in: C:\Program Files (x86)\MeGUI_2507_x86\...
Use a folder created by the user, for instance: C:\Portable\MeGUI...

b) Don't put data in root folder: C:\MOVIE.mkv
Use a folder created by the user, for instance: C:\Data\MOVIE.mkv