@dae, just got the same error:
Debug info:
Anki 2.1.48 (fb07bad3) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
Platform: Windows 10
Flags: frz=True ao=True sv=3
Add-ons, last update check: 2021-09-22 20:42:12
Caught exception:
Traceback (most recent call last):
File “aqt\taskman.py”, line 101, in _on_closures_pending
File “aqt\taskman.py”, line 71, in
File “aqt\sound.py”, line 289, in
File “aqt\tts.py”, line 573, in _on_done
File “concurrent\futures_base.py”, line 432, in result
File “concurrent\futures_base.py”, line 388, in __get_result
File “concurrent\futures\thread.py”, line 57, in run
File “aqt\sound.py”, line 289, in
File “aqt\tts.py”, line 569, in _play
File “asyncio\runners.py”, line 44, in run
File “asyncio\base_events.py”, line 616, in run_until_complete
File “aqt\tts.py”, line 604, in speakText
FileNotFoundError: [Errno 2] No such file or directory: ‘C:\Users\sergi\AppData\Local\Temp\anki_temp\tts.wav’
Restarting Anki solves the problem.