Parsing error for "apropos"

[Joshua-Hwang]

Debug info:
Anki 2.1.38 (355e4cd5) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
Platform: Windows 10
Flags: frz=True ao=True sv=1
Add-ons, last update check: 2021-02-08 23:06:57

Caught exception:
Traceback (most recent call last):
  File "aqt\webview.py", line 515, in handler
  File "aqt\editor.py", line 508, in <lambda>
  File "C:\Users\joshua\AppData\Roaming\Anki2\addons21\2136497008\autodefine.py", line 99, in <lambda>
    editor.saveNow(lambda: _get_definition(editor, force_pronounce, force_definition, force_phonetic_transcription))
  File "C:\Users\joshua\AppData\Roaming\Anki2\addons21\2136497008\autodefine.py", line 278, in _get_definition
    all_sounds.append(editor.urlToLink(wav_url).strip())
AttributeError: 'NoneType' object has no attribute 'strip'