Very nasty error after rating in reviewer

[galantra]

In the reviewer, immediately after rating my recall, I sometimes get an error. This is the info provided by the debug add-on:

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 (6661ba8a) Python 3.6.7 Qt 5.12.1 PyQt 5.11.3
Platform: Windows 10
Flags: frz=True ao=True sv=1

Caught exception:
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\653807651\__init__.py", line 118, in answerCaller
    return onAnswerButton(int(closureKey))
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\653807651\__init__.py", line 94, in onAnswerButton
    self._answerCard(number)
  File "<decorator-gen-298>", line 2, in newAnswerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 65, in repl
  File "<decorator-gen-272>", line 2, in newAnswerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 71, in repl
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\935264945\main.py", line 214, in answerCard
    _old(self, ease)
  File "<decorator-gen-268>", line 2, in newAnswerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 69, in repl
  File "<decorator-gen-228>", line 2, in newAnswerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 69, in repl
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\653807651\__init__.py", line 56, in newAnswerCard
    _oldAnswerCard(self, ease)
  File "<decorator-gen-18>", line 2, in _answerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 69, in repl
  File "aqt\reviewer.py", line 237, in _answerCard
  File "<decorator-gen-176>", line 2, in answerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 65, in repl
  File "<decorator-gen-114>", line 2, in answerCard
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 71, in repl
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\1758624338\hoardersDelight.py", line 125, in sd_answerCard
    return _old(self, card, ease)
  File "anki\sched.py", line 87, in answerCard
  File "anki\sched.py", line 797, in _answerRevCard
  File "<decorator-gen-20>", line 2, in _rescheduleRev
  File "anki\hooks.py", line 74, in decorator_wrapper
  File "anki\hooks.py", line 66, in repl
  File "C:\Users\user\AppData\Roaming\Anki2\addons21\1130426680\Straight_Reward.py", line 36, in rescheduleRevReward
    if ease == 3 and count > 0 and count % THRESHOLD == THRESHOLD - 1:
<class 'TypeError'>: '>' not supported between instances of 'NoneType' and 'int'

I have only a faint idea of software coding.
I recently switched to 2.1 and installed many add-ons, including yours. I believe the error is caused by ease factor.

[luminousspice]

According to the error message, It seems that this addon conflicts with the other addon.
So, this addon can't count pushing [good] button from the learning history.