Has anyone ever got this to work? I have tried everything I can think of and whatever I try I get a message saying "Fail! Prompt file uploaded fail. Please check your file name, format or length."

I am trying to upload a user prompt into Index 1, so I have named the file vigorpbx_userprompt01.wav as instructed on the PBX Prompt Maintenance page. One thing I would note is that the template is actually vigorpbx_userpromptxxx.wav, with three xs for the index number, but the text then confusingly suggests that you only use two numbers for the index, so that is what I have done.

I have tried other filenames just to rule this out as the problem, but it does not make any difference.

I am using Audacity to record the prompt, sampled at 44.1kHz, which is about as standard as you can get, and the project plays back fine on my computer.

I have tried exporting it as the following encoding within the wav wrapper, but none of them is accepted:

unsigned 8-bit PCM
signed 16-bit PCM
U-law
A-law

All these seem to be within the parameters specified, but are not accepted. The largest size the file has been is 5.1MB (this obviously depends on which codec is employed), so that is not the problem either.

When I click on Restore, having selected the file, the UI displays "Uploading and converting codec!" with a moving animation for a second or so, before displaying the error message. Does this function ever work, and if so what is the trick, or is it broken?

This guide covers how it should work: https://www.draytek.co.uk/support/guides/kb-bx2000-prompts#creating-prompt-files

When putting G.711 prompts on to the PBX, it's best to do sample rate conversion from the PC and it should be 8000Hz. A-law should be correct for the UK, though that probably matters less these days.

Looking at some old files the format should be like this "vigorpbx_userprompt05.wav"

Just realised that I never followed up on this issue here. I was able to successfully install the prompt from a Windows 10 PC using Firefox rather than from Safari on a Mac, which just doesn't work.

I didn't try Firefox from a Mac but next time I want to install a prompt I will try this.