Voicemail transcription no longer working — HTTP 403 from storage.googleapis.com

[Morgane]

Hello,

Infos :
v20.0.9.995 — engine 3CX, language fr-FR.
Since 2026-08-21 around 10:00 (+02:00), voicemails are emailed with the WAV but without transcription.

The upload of the audio file to your transcription bucket is rejected with HTTP 403.
Example — ext. 292, vmail_0781056340_292_20260821161018.wav, from 3CXGatewayService.log:

18:11:31.831 POST https://wmr.3cx.net/manager/requestaiconversion -> 200
18:11:31.873 PUT https://storage.googleapis.com/transcriber-eu/wav/b/1/*************....wav?*
18:11:31.935 Received HTTP response headers after 61.79ms - 403
18:11:31.935 [GoogleSignedUrlUploader] GoogleSignedUrlUploader returned Forbidden
18:12:30.933 Signed URL Upload attempt V174 2/3 -> 403 (same URL, same file)
18:21:31.815 Transcription timed out for 292/vmail_0781056340_292_20260821161018

This affects most voicemails (18 of 29 uploads failed on 21 Aug) across several extensions.
All requests to wmr.3cx.net return 200, so only the upload to Google Cloud Storage is failing.

Could you check the transcriber-eu bucket / WMR node for our tenant ?

Thanks a lot !

 

[Morgane]

Nothing is currently published on status.3cx.net, but a comparable platform-side transcription degradation was posted there on 20 Aug 2025.

One question that may shortcut the investigation: was any credential rotated or renewed around 2026-08-21 on the transcription path (service-account key used to sign the URLs, bucket IAM bindings, WMR node certificates)? A stale signing key alone would not explain the intermittency, but a partial rotation across the WMR fleet, or IAM propagation on the transcriber-eu bucket, would ?

 

[Morgane]

Sorry, I forgot to mention: this is a 3CX-HOSTED instance

 

[NikosT_3CX]

@Morgane as I can see your license key is 3CX AI.

The available options for transcription are Google, OpenAI, and Grok.

https://www.3cx.com/docs/voicemail-transcription/
https://www.3cx.com/docs/openai-transcription/
https://www.3cx.com/blog/releases/ai-transcription-grok/

Can you setup one of these and then check again ?