Trouble Adding Audio to a File

[KayB]

So I have an approximately four hour long video (it's actually three separate videos appended together using avidemux), but I recorded the audio separately (also four hours long, AC3, 3 chan, 40 kbps according to avidemux, but recorded as 44kHz 16bit AAC128 256kbps). I want to replace the audio of the video with my own recorded .AAC file, so I went to select track, unchecked the video audio, and selected my new audio file. However, when I went to export/save the whole thing, the end result was a corrupted video. When I looked at advanced settings during the export process, the video and total size were increasing, but the audio size stayed at either 0 or 1 MB.

When I didn't add the audio and just exported the video with it's default audio, the video exported just fine. I've tried using 2.6 and 2.7, and I've also tried redownloading the software just in case, but neither solved the issue. Neither the video files or the audio files are corrupted. Is there anyway where I can fix this?

Sorry if this sounds like a stupid question, am very new to this.

[eumagga0x2a]

Please try the latest nightly matching your operating system first. If the problem (misdetection of audio type) persists, please provide a sample (as short as reasonably possible). In general, add external track as uncompressed .wav and encode it during saving the video in Avidemux.