31402: UserMedia Acquisition Failed

This error occurs when the browser has microphone permission, but the Voice JavaScript SDK cannot acquire the input media stream for a call. This usually points to an invalid device selection, overly restrictive getUserMedia() constraints, or a browser, operating system, or hardware issue.

• A deviceId passed to device.audio.setInputDevice() does not exist or is no longer available.
• The rtcConstraints passed to device.connect() are too restrictive, so getUserMedia() cannot match an available device.
• Audio constraints applied with device.audio.setAudioConstraints() cannot be satisfied by the selected microphone.
• The browser, operating system, or local audio hardware cannot provide the microphone stream even after permission is granted.

• Verify that the selected microphone exists in device.audio.availableInputDevices before you call device.audio.setInputDevice().
• Remove custom rtcConstraints or other audio constraints and test again with a simpler input request such as audio: true.
• If you apply constraints with device.audio.setAudioConstraints(), clear them with device.audio.unsetAudioConstraints() and retry.
• Call getUserMedia() before you create the Device so you can detect microphone and device issues earlier and refresh the available device list before a call starts.
• Test with the default input device first, then confirm the microphone works in the browser and operating system.

• Voice JavaScript SDK: Twilio.Device
• Twilio.Device.audio
• Voice JavaScript SDK: Best Practices