I have the exact same problem on MacOS Monterey since installing version 6.0. Here's the content of my debug log:
Spoiler:
Failed to initialize plugin: '/Users/marcoligtenberg/Library/Preferences/calibre/plugins/BOL_NL.zip'
Traceback (most recent call last):
File "calibre_plugins.BOL_NL.__init__", line 42, in <module>
from PyQt5 import Qt as QtGui
ImportError: cannot import name 'Qt' from 'qt' (/Applications/calibre.app/Contents/Frameworks/plugins/python-lib.bypy.frozen/qt/__init__.pyc)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "calibre/customize/ui.py", line 740, in initialize_plugins
File "calibre/customize/ui.py", line 64, in load_plugin
File "calibre/customize/zipplugin.py", line 304, in load
File "importlib/__init__.py", line 126, in import_module
File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
File "calibre/customize/zipplugin.py", line 203, in exec_module
File "calibre_plugins.BOL_NL.__init__", line 44, in <module>
from PyQt4 import QtGui
ModuleNotFoundError: No module named 'PyQt4'
calibre Debug log
calibre 6.0 embedded-python: True
macOS-12.4-arm64-arm-64bit Darwin ('64bit', '')
('Darwin', '21.5.0', 'Darwin Kernel Version 21.5.0: Tue Apr 26 21:08:29 PDT 2022; root:xnu-8020.121.3~4/RELEASE_ARM64_T8101')
Python 3.10.1
OSX: ('12.4', ('', '', ''), 'arm64')
Interface language: None
Successfully initialized third party plugins: DeDRM (7, 2, 1) && Kobo Books (1, 9, 2) && Kobo Utilities (2, 16, 3)
calibre 6.0 embedded-python: True
macOS-12.4-arm64-arm-64bit Darwin ('64bit', '')
('Darwin', '21.5.0', 'Darwin Kernel Version 21.5.0: Tue Apr 26 21:08:29 PDT 2022; root:xnu-8020.121.3~4/RELEASE_ARM64_T8101')
Python 3.10.1
OSX: ('12.4', ('', '', ''), 'arm64')
Interface language: None
Successfully initialized third party plugins: DeDRM (7, 2, 1) && Kobo Books (1, 9, 2) && Kobo Utilities (2, 16, 3)
devicePixelRatio: 2.0
logicalDpi: 72.0 x 72.0
physicalDpi: 108.50000162950651 x 107.50000161448803
Using calibre Qt style: True
[0.00] Starting up...
[0.01] Showing splash screen...
[0.15] splash screen shown
[0.15] Initializing db...
[0.63] db initialized
[0.63] Constructing main UI...
DEBUG: 0.0 Kobo Utilities Configuration - CreateNewCustomColumn is supported
DEBUG: 0.0 KoboUtilites::action.py - loading translations
DEBUG: 0.0 KoboUtilites::dialogs.py - loading translations
DEBUG: 0.0 KoboUtilites::action.py - loading translations
DEBUG: 0.9 No Kobo Touch, Glo or Mini appears to be connected
DEBUG: 0.9 rebuild_menus - self.supports_ratings=None, self.supports_tiles=None
DEBUG: 0.9 KoboUtilities:set_toolbar_button_tooltip - start: text='None'
DEBUG: 0.9 device_driver_name - could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
DEBUG: 0.9 KoboUtilities:set_toolbar_button_tooltip - setting to text='Utilities to use with Kobo ereaders
Driver: KoboTouch'
DEBUG: 0.9 device_driver_name - could not load extended driver. Exception= No module named 'calibre_plugins.kobotouch_extended'
[1.61] main UI initialized...
[1.61] Hiding splash screen
Starting QuickView
Failed to initialize plugin: '/Users/marcoligtenberg/Library/Preferences/calibre/plugins/BOL_NL.zip'
DeDRM v7.2.1: Trying to decrypt Gort, Ilja - Vrije vogels (2022).epub
DeDRM v7.2.1: Verifying zip archive integrity
WARNING: /Applications/calibre.app/Contents/MacOS/calibre-parallel is loading libcrypto in an unsafe way
[10.34] splash screen hidden
[10.34] Started up in 10.34 seconds with 35476 books
Debugging DND event
text/uri-list 66 b'file:///Users/marcoligtenberg/Desktop/Bed%20en%20Breakfast.epub/\r\n'
Firefox rurl: None None
URLS: ['file:///Users/marcoligtenberg/Desktop/Bed%20en%20Breakfast.epub/']
Paths: ['/Users/marcoligtenberg/Desktop/Bed en Breakfast.epub/']
Extensions: frozenset({'epub/'})
Debugging DND event
text/uri-list 87 b'file:///Users/marcoligtenberg/Desktop/Gort,%20Ilja%20-%20Vrije%20vogels%20(2022).epub\r\n'
Firefox rurl: None None
URLS: ['file:///Users/marcoligtenberg/Desktop/Gort,%20Ilja%20-%20Vrije%20vogels%20(2022).epub']
Paths: ['/Users/marcoligtenberg/Desktop/Gort, Ilja - Vrije vogels (2022).epub']
Extensions: frozenset({'epub'})
2022-07-11 11:48:20.523 calibre-debug[1143:14974] TSMSendMessageToUIServer: CFMessagePortSendRequest FAILED(-1) to send to port com.apple.tsm.uiserver
2022-07-11 11:48:20.524 calibre-debug[1143:14974] TSMSendMessageToUIServer: CFMessagePortSendRequest FAILED(-1) to send to port com.apple.tsm.uiserver
2022-07-11 11:48:20.524 calibre-debug[1143:14974] TSMSendMessageToUIServer: CFMessagePortSendRequest FAILED(-1) to send to port com.apple.tsm.uiserver
Failed to initialize plugin: '/Users/marcoligtenberg/Library/Preferences/calibre/plugins/BOL_NL.zip'
DeDRM v7.2.1: Trying to decrypt Ilja Gort - Godendrank.epub
DeDRM v7.2.1: Verifying zip archive integrity
WARNING: /Applications/calibre.app/Contents/MacOS/calibre-parallel is loading libcrypto in an unsafe way
Debugging DND event
text/uri-list 73 b'file:///Users/marcoligtenberg/Desktop/Ilja%20Gort%20-%20Godendrank.epub\r\n'
Firefox rurl: None None
URLS: ['file:///Users/marcoligtenberg/Desktop/Ilja%20Gort%20-%20Godendrank.epub']
Paths: ['/Users/marcoligtenberg/Desktop/Ilja Gort - Godendrank.epub']
Extensions: frozenset({'epub'})