From time to time, I ran into this issue, but only today occurred a situation that could provide a explanation.

I was reading something (a mail, a web page, I don't remember), and maybe I stopped the voice and then received one or more notify by WhatsApp app, or first I received a first notify and then stopped voice, I don't remember exactly. From that moment, voice completely disappeared (log provided below).

I don't know whether it's important, but I use WASAPI in NVDA, even if I disabled exclusive mode checkboxes in current audio device properties.

Steps to reproduce:

Unable to provide.

Actual behavior:

Voice disappeared, until I restarted NVDA.

Expected behavior:

Voice should recover itself without restarting NVDA.

NVDA logs, crash dumps and other attachments:

ERROR - logHandler._threadExceptHook (13:48:18.521) - Thread-2 (14032):
Exception in thread Thread-2:
Traceback (most recent call last):
  File "threading.pyc", line 1045, in _bootstrap_inner
  File "C:\Users\Admin\AppData\Roaming\nvda\addons\Eloquence\synthDrivers\_eloquence.py", line 109, in run
    player.stop()
  File "nvwave.pyc", line 978, in stop
  File "_ctypes/callproc.c", line 1000, in GetResult
OSError: [WinError -2004287477] Windows Error 0x8889000b
ERROR - comtypes._comobject.call_without_this (13:48:39.865) - Dummy-4 (6804):
Exception in IUIAutomationEventHandler.HandleAutomationEvent implementation:
Traceback (most recent call last):
  File "comtypes\_comobject.pyc", line 176, in call_without_this
  File "UIAHandler\__init__.pyc", line 747, in IUIAutomationEventHandler_HandleAutomationEvent
  File "comtypes\_post_coinit\unknwn.pyc", line 115, in __getattr__
_ctypes.COMError: (-2147220991, 'An event was unable to invoke any of the subscribers', (None, None, None, 0, None))

Last block is repeated for many times.

System configuration

NVDA installed/portable/running from source:

Installed.

NVDA version:

NVDA alpha-33864,7e526e81

Windows version:

Windows 10 Version 22H2 (build SO 19045.4842)

Name and version of other software in use when reproducing the issue:

WhatsApp app from Microsoft Store.

Other information about your system:

None.

Other questions

Does the issue still occur after restarting your computer?

Yes.

Have you tried any other versions of NVDA? If so, please report their behaviors.

I'm sure it's happened something similar in previous alphas.

If NVDA add-ons are disabled, is your problem still occurring?

Not tested.

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

Not tested (but I ran the tool recently).