[gavinallen50]

I haven't used it for a few weeks but Calibre has suddenly stopped working.

I haven't installed anything new recently, just the usual windows updates. The is no error in the Event Viewer.

I have tested the following:

Normal - doesn't start
Normal (with all services and startup apps disabled) - doesn't start
Safe Mode - works

The only way I've managed to get it to start is if I disable my Display Adapter in Device Manager...then it starts fine.

I've tried updating my graphics driver to the latest version with no effect. I've also tried old version of Calibre with no effect.

Here is the output from calibre-debug:

with display adapter disabled Calibre opens successfully:

C:\WINDOWS\system32>calibre-debug -g
calibre 7.21 embedded-python: True
Windows-10-10.0.19045-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19045')
Python 3.11.5
Windows: ('10', '10.0.19045', 'SP0', 'Multiprocessor Free')
Interface language: None
EXE path: C:\Program Files\Calibre2\calibre-debug.exe
Successfully initialized third party plugins:
QPA platform: windows
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 108.91792294807368 x 108.85714285714285
Using calibre Qt style: False
[0.00] Starting up...
[0.00] Showing splash screen...
[1.22] splash screen shown
[1.22] Initializing db...
[2.27] db initialized
[2.27] Constructing main UI...
[4.08] GUI main window shown
[4.17] main UI initialized...
[4.17] Hiding splash screen
[4.17] splash screen hidden
[4.17] Started up in 4.17 seconds with 10826 books


with display adapter enabled I get this output but nothing else:

C:\WINDOWS\system32>calibre-debug -g
calibre 7.21 embedded-python: True
Windows-10-10.0.19045-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.19045')
Python 3.11.5
Windows: ('10', '10.0.19045', 'SP0', 'Multiprocessor Free')
Interface language: None
EXE path: C:\Program Files\Calibre2\calibre-debug.exe
Successfully initialized third party plugins:





Thanks.