Replay buttons on card plugin not working for Anki 2.1.15

[bgx90]

I'm using Anki version 2.1.15. When I open a deck I get the following error:

An error occurred. Please start Anki while holding down the shift key, which will temporarily disable the add-ons you have installed. 
If the issue only occurs when add-ons are enabled, please use the Tools>Add-ons menu item to disable some add-ons and restart Anki, repeating until you discover the add-on that is causing the problem. 
When you've discovered the add-on that is causing the problem, please report the issue on the add-ons section of our support site. 
Debug info:
Anki 2.1.15 (442df9d6) Python 3.9.2 Qt 5.15.2 PyQt 5.15.2
Platform: Linux
Flags: frz=False ao=True sv=1
Add-ons possibly involved: Replay buttons on card

Caught exception:
  File "/usr/share/anki/aqt/webview.py", line 27, in cmd
    return json.dumps(self.onCmd(str))
  File "/usr/share/anki/aqt/webview.py", line 87, in _onCmd
    return self._onBridgeCmd(str)
  File "/usr/share/anki/aqt/webview.py", line 386, in _onBridgeCmd
    return self.onBridgeCmd(cmd)
  File "/usr/share/anki/aqt/overview.py", line 37, in _linkHandler
    self.mw.moveToState("review")
  File "/usr/share/anki/aqt/main.py", line 486, in moveToState
    getattr(self, "_"+state+"State")(oldState, *args)
  File "/usr/share/anki/aqt/main.py", line 516, in _reviewState
    self.reviewer.show()
  File "<decorator-gen-24>", line 2, in show
  File "/usr/share/anki/anki/hooks.py", line 74, in decorator_wrapper
    return repl(*args, **kwargs)
  File "/usr/share/anki/anki/hooks.py", line 65, in repl
    old(*args, **kwargs)
  File "/usr/share/anki/aqt/reviewer.py", line 46, in show
    self.nextCard()
  File "/usr/share/anki/aqt/reviewer.py", line 96, in nextCard
    self._showQuestion()
  File "/usr/share/anki/aqt/reviewer.py", line 168, in _showQuestion
    q = c.q()
  File "/usr/share/anki/anki/cards.py", line 120, in q
    return self.css() + self._getQA(reload, browser)['q']
  File "/usr/share/anki/anki/cards.py", line 137, in _getQA
    self._qa = self.col._renderQA(data, *args)
  File "/usr/share/anki/anki/collection.py", line 591, in _renderQA
    d[type] = runFilter(
  File "/usr/share/anki/anki/hooks.py", line 39, in runFilter
    arg = func(arg, *args)
  File "/home/user/.local/share/Anki2/addons21/498789867/__init__.py", line 95, in play_button_filter
    return re.sub(sound_re, add_button, qa_html)
  File "/usr/lib/python3.9/re.py", line 210, in sub
    return _compile(pattern, flags).sub(repl, string, count)
  File "/home/user/.local/share/Anki2/addons21/498789867/__init__.py", line 80, in add_button
    unescaped_fn = html.parser.HTMLParser().unescape(fn)
<class 'AttributeError'>: 'HTMLParser' object has no attribute 'unescape'```

[tjthejuggler]

Still happening for me too

Error
An error occurred. Please start Anki while holding down the shift key, which will temporarily disable the add-ons you have installed.
If the issue only occurs when add-ons are enabled, please use the Tools>Add-ons menu item to disable some add-ons and restart Anki, repeating until you discover the add-on that is causing the problem.
When you've discovered the add-on that is causing the problem, please report the issue on the add-ons section of our support site.
Debug info:
Anki 2.1.15 (442df9d6) Python 3.9.7 Qt 5.15.2 PyQt 5.15.4
Platform: Linux
Flags: frz=False ao=True sv=1
Add-ons possibly involved: Replay buttons on card

Caught exception:
File "/usr/share/anki/aqt/webview.py", line 27, in cmd
return json.dumps(self.onCmd(str))
File "/usr/share/anki/aqt/webview.py", line 87, in _onCmd
return self._onBridgeCmd(str)
File "/usr/share/anki/aqt/webview.py", line 386, in _onBridgeCmd
return self.onBridgeCmd(cmd)
File "/usr/share/anki/aqt/overview.py", line 37, in linkHandler
self.mw.moveToState("review")
File "/usr/share/anki/aqt/main.py", line 486, in moveToState
getattr(self, ""+state+"State")(oldState, *args)
File "/usr/share/anki/aqt/main.py", line 516, in _reviewState
self.reviewer.show()
File "/usr/share/anki/aqt/reviewer.py", line 46, in show
self.nextCard()
File "/usr/share/anki/aqt/reviewer.py", line 96, in nextCard
self._showQuestion()
File "/usr/share/anki/aqt/reviewer.py", line 168, in _showQuestion
q = c.q()
File "/usr/share/anki/anki/cards.py", line 120, in q
return self.css() + self._getQA(reload, browser)['q']
File "/usr/share/anki/anki/cards.py", line 137, in _getQA
self._qa = self.col._renderQA(data, *args)
File "/usr/share/anki/anki/collection.py", line 591, in _renderQA
d[type] = runFilter(
File "/usr/share/anki/anki/hooks.py", line 39, in runFilter
arg = func(arg, *args)
File "/home/tim/.local/share/Anki2/addons21/498789867/init.py", line 95, in play_button_filter
return re.sub(sound_re, add_button, qa_html)
File "/usr/lib/python3.9/re.py", line 210, in sub
return _compile(pattern, flags).sub(repl, string, count)
File "/home/tim/.local/share/Anki2/addons21/498789867/init.py", line 80, in add_button
unescaped_fn = html.parser.HTMLParser().unescape(fn)
<class 'AttributeError'>: 'HTMLParser' object has no attribute 'unescape'