Audio file not retrieved

Hi our NGO investigators in Nepal are having a problem uploading audio files. Here are two sample messages that we see when we look at the data. THese are error messages for a question that uses an “audio” answer.

Could not retrieve Nov 11, 11.04 AM​-11_4_32.aac and
Could not retrieve 11 Nov, 11.00 am-11_1_15.mp3

Welcome to the community, @laufsmartvillages! Could you also let the community know the mode of data collection (Collect android app or Enketo) you are using for this audio? Were you successful to submit the same to the server?

Thanks so much for your attention.
Yes they used android devices. Since uploading my query, I also found that the audio files exist, and need to be downloaded separately. Is there a more efficient way of doing this. Since these are audio files for different questions and there are many responses. So we will have quite a large number of audio files that need to be linked to each survey response for analysis.
I believe there is an update that helps us download the audio files as part of the xls -do let me know how I can use this.
Any other suggestions would be very welcome!

@laufsmartvillages, maybe this post discussed previously should help you solve your issue: