SAPI 4 synthesizer not loading anymore

[Mohamed00]

Steps to reproduce:

1. Install the latest NVDA alpha.
2. Load SAPI 4.

Actual behavior:

SAPI 4 doesn't load.

Expected behavior:

SAPI 4 should load.

NVDA logs, crash dumps and other attachments:

Log fragment when loading SAPI 4.
ERROR - synthDriverHandler.setSynth (11:44:19.579) - MainThread (11820):
setSynth failed for sapi4
Traceback (most recent call last):
File "synthDriverHandler.pyc", line 483, in setSynth
File "synthDriverHandler.pyc", line 446, in getSynthInstance
File "synthDrivers\sapi4.pyc", line 127, in init
File "synthDrivers\sapi4.pyc", line 236, in _set_voice
ctypes.ArgumentError: argument 1: TypeError: wrong type
DEBUGWARNING - synthDrivers.sapi4.SynthDriverBufSink.IUnknown_Release (11:44:19.649) - MainThread (11820):
ITTSBufNotifySink::Release called too many times by engine

System configuration

NVDA installed/portable/running from source:

Installed.

NVDA version:

alpha-34782,82fefa5a.

Windows version:

Windows 11, Version 24H2 (OS Build 26100.2605).

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

N/A.

Other information about your system:

N/A.

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.

Yes, the last version where this worked was alpha-34772,c3e899a8.

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

Yes.

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

Yes.