This error message happened while I was trying to update the Ankimon add-on.
Error message (don't change this)
Anki 23.12.1 (1a1d4d54)  (ao)
Python 3.9.15 Qt 6.6.1 PyQt 6.6.1
Platform: Windows-10-10.0.22631
Traceback (most recent call last):
  File "aqt.taskman", line 142, in _on_closures_pending
  File "aqt.taskman", line 86, in <lambda>
  File "decorator", line 232, in fun
  File "anki.hooks", line 89, in decorator_wrapper
  File "anki.hooks", line 86, in repl
  File "C:\Users\ruper\AppData\Roaming\Anki2\addons21\1322529746\gui\addons.py", line 35, in _check_future_for_exceptions
    _old(*args, **kwargs)
  File "aqt.addons", line 1203, in _download_done
  File "concurrent.futures._base", line 439, in result
  File "concurrent.futures._base", line 391, in __get_result
  File "concurrent.futures.thread", line 58, in run
  File "aqt.addons", line 1180, in <lambda>
  File "aqt.addons", line 1196, in _download_all
  File "aqt.addons", line 1141, in download_and_install_addon
  File "aqt.addons", line 467, in install
  File "aqt.addons", line 491, in _install
  File "aqt.addons", line 733, in backupUserFiles
PermissionError: [WinError 5] Access is denied: 'C:\\Users\\ruper\\AppData\\Roaming\\Anki2\\addons21\\1908235722\\user_files' -> 'C:\\Users\\ruper\\AppData\\Roaming\\Anki2\\addons21\\files_backup'