MobileRead Forums - View Single Post

7e-ross · 12-21-2025, 11:02 PM

As of the last 24 hours, Calibre will launch, with splash screen, but the window will be invisible. Task manager will acknowledge it is running, but hovering over the taskbar icon will show an empty window. Rolled it all the way back to v7.15 in hopes of getting something and finally caught an error message.

"calibre, version 7.15.0
ERROR: Startup error: There was an error during calibre startup. Parts of calibre may not function. Click "Show details" to learn more.

Traceback (most recent call last):
File "calibre\gui2\main.py", line 307, in initialize_db_stage2
File "calibre\gui2\main.py", line 250, in start_gui
File "calibre\gui2\ui.py", line 247, in initialize
File "calibre\gui2\layout.py", line 333, in init_main_window_mixin
File "calibre\gui2\bars.py", line 757, in __init__
File "calibre\gui2\bars.py", line 823, in apply_settings
KeyError: 'mid-small' "

Help would be appreciated.

12-21-2025, 11:02 PM	#1
7e-ross Junior Member Posts: 2 Karma: 10 Join Date: Dec 2025 Device: Kindle Fire 7	What does this error mean? (windows10) As of the last 24 hours, Calibre will launch, with splash screen, but the window will be invisible. Task manager will acknowledge it is running, but hovering over the taskbar icon will show an empty window. Rolled it all the way back to v7.15 in hopes of getting something and finally caught an error message. "calibre, version 7.15.0 ERROR: Startup error: There was an error during calibre startup. Parts of calibre may not function. Click "Show details" to learn more. Traceback (most recent call last): File "calibre\gui2\main.py", line 307, in initialize_db_stage2 File "calibre\gui2\main.py", line 250, in start_gui File "calibre\gui2\ui.py", line 247, in initialize File "calibre\gui2\layout.py", line 333, in init_main_window_mixin File "calibre\gui2\bars.py", line 757, in __init__ File "calibre\gui2\bars.py", line 823, in apply_settings KeyError: 'mid-small' " Help would be appreciated.