Anki crashes all the time two days before exam :(

I tried restarting it while holding shift and also looked through the toolbox. I restarted Anki and the computer multiple times. Please help me.

Error

Anki 2.1.49 (dc80804a) Python 3.8.6 Qt 5.14.2 PyQt 5.14.2
Platform: Windows 10
Flags: frz=True ao=False sv=2
Add-ons, last update check: 2022-04-23 23:41:51

Caught exception:
Traceback (most recent call last):
File “aqt\webview.py”, line 541, in handler
File “aqt\reviewer.py”, line 704, in _onTypedAnswer
File “aqt\reviewer.py”, line 383, in _showAnswer
File “aqt\reviewer.py”, line 759, in _showEaseButtons
File “aqt\reviewer.py”, line 846, in _answerButtons
File “aqt\reviewer.py”, line 832, in but
File “aqt\reviewer.py”, line 856, in _buttonTime
File “anki\scheduler\v2.py”, line 1140, in nextIvlStr
File “anki\scheduler\v2.py”, line 1035, in nextIvl
File “anki\scheduler\v2.py”, line 914, in _nextRevIvl
File “anki\scheduler\v2.py”, line 949, in _constrainedIvl
TypeError: unsupported operand type(s) for *: ‘float’ and ‘NoneType’

Please follow the steps on When problems occur - Frequently Asked Questions