Calibre won't open when updated after 7.6

[Aliandry]

I had this issue a long time ago when I updated (perhaps from 7.6 to 7.7), and I could not get the program to open at all so I just uninstalled it and reinstalled 7.6.

I tried to install the 7.15 today. Same thing happens. It does not show up in the running apps, it isn't open out of sight. There's no activity.

I started a command prompt and ran "calibre-debug -g". Here's what it gave me:

C:\Users\X>calibre-debug -g
Python path configuration:
PYTHONHOME = (not set)
PYTHONPATH = (not set)
program name = 'C:\Program Files\Calibre2\calibre-debug.exe'
isolated = 1
environment = 0
user site = 0
safe_path = 1
import site = 1
is in build tree = 0
stdlib dir = ''
sys._base_executable = 'C:\\Program Files\\Calibre2\\calibre-debug.exe'
sys.base_prefix = 'C:\\Users\\X'
sys.base_exec_prefix = 'C:\\Users\\X'
sys.platlibdir = 'DLLs'
sys.executable = 'C:\\Program Files\\Calibre2\\calibre-debug.exe'
sys.prefix = 'C:\\Users\\X'
sys.exec_prefix = 'C:\\Users\\X'
sys.path = [
]
Fatal Python error: init_fs_encoding: failed to get the Python codec of the filesystem encoding
Python runtime state: core initialized
Traceback (most recent call last):
File "<frozen importlib._bootstrap>", line 1176, in _find_and_load
File "<frozen importlib._bootstrap>", line 1147, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 690, in _load_unlocked
File "bypy-importer.py", line 275, in exec_module
File "bypy-importer.py", line 63, in get_module_code
ValueError: bad marshal data (unknown type code)

Extension modules: bypy_frozen_importer (total: 1)

I'd appreciate some help. I use Calibre almost everyday and it's unfortunate I cannot update it.

[Aliandry]

Last time I tried repairing it, reinstalling it, the works and nothing solved it, but this time repairing it and restarting the pc seems to have worked!

I'm so glad.