Critical Error when opening books in Calibre

[tdeboor]

First time posting, so if I mess it up a bit please be kind.

When I initially open Calibre and select a book I can open it with no problems. If I close that book and try to open another I receive a "Critical Error" message. I ran Calibre in debug mode and got the following log file:

Spoiler:

calibre Debug log
calibre 3.39 [64bit] embedded-python: True is64bit: True
Windows-10-10.0.17763-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.17763')
Python 2.7.15+
Windows: ('10', '10.0.17763', 'SP0', u'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 12, 1) && DeDRM (6, 5, 3) && Package KFX (from KFX Input) (1, 12, 1) && Obok DeDRM (6, 5, 3) && EpubSplit (2, 6, 0) && KFX metadata reader (from KFX Input) (1, 12, 1) && KFX Input (1, 12, 1)
calibre 3.39 [64bit] embedded-python: True is64bit: True
Windows-10-10.0.17763-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.17763')
Python 2.7.15+
Windows: ('10', '10.0.17763', 'SP0', u'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 12, 1) && DeDRM (6, 5, 3) && Package KFX (from KFX Input) (1, 12, 1) && Obok DeDRM (6, 5, 3) && EpubSplit (2, 6, 0) && KFX metadata reader (from KFX Input) (1, 12, 1) && KFX Input (1, 12, 1)
Turning on automatic hidpi scaling
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 95.8113948919 x 95.9160839161
Using calibre Qt style: True
[0.00] Starting up...
[0.00] Showing splash screen...
[0.08] splash screen shown
[0.08] Initializing db...
[0.12] db initialized
[0.12] Constructing main UI...
DEBUG: 0.0 obok::utilities.py - loading translations
DEBUG: 0.0 obok::dialogs.py - loading translations
DEBUG: 0.0 obok::config.py - loading translations
DEBUG: 0.0 obok::action_err.py - loading translations
[1.76] main UI initialized...
[1.76] Hiding splash screen
[24.92] splash screen hidden
[24.92] Started up in 24.92 seconds with 655 books
Worker Launch took: 0.131999969482
calibre 3.39 [64bit] embedded-python: True is64bit: True
Windows-10-10.0.17763-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.17763')
Python 2.7.15+
Windows: ('10', '10.0.17763', 'SP0', u'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 12, 1) && DeDRM (6, 5, 3) && Package KFX (from KFX Input) (1, 12, 1) && Obok DeDRM (6, 5, 3) && EpubSplit (2, 6, 0) && KFX metadata reader (from KFX Input) (1, 12, 1) && KFX Input (1, 12, 1)
Traceback (most recent call last):
File "site-packages\calibre\gui2\actions\view.py", line 106, in view_format_by_id
File "site-packages\calibre\gui2\actions\view.py", line 155, in _view_file
File "site-packages\calibre\gui2\actions\view.py", line 125, in _launch_viewer
File "site-packages\calibre\gui2\jobs.py", line 284, in launch_gui_app
File "site-packages\calibre\utils\ipc\server.py", line 247, in run_job
File "site-packages\calibre\utils\ipc\server.py", line 220, in launch_worker
CriticalError: Failed to launch worker process:
Traceback (most recent call last):
File "site-packages\calibre\utils\ipc\server.py", line 230, in do_launch
File "site-packages\calibre\utils\ipc\__init__.py", line 22, in eintr_retry_call
File "multiprocessing\connection.py", line 147, in accept
File "multiprocessing\connection.py", line 420, in deliver_challenge
IOError: [Errno 232] The pipe is being closed


QWindowsWindow::setGeometry: Unable to set geometry 492x192+714+480 on QWidgetWindow/'DialogWindow'. Resulting geometry: 492x218+714+480 (frame: 8, 31, 8, 8, custom margin: 0, 0, 0, 0, minimum size: 492x192, maximum size: 16777215x16777215).
calibre 3.39 [64bit] embedded-python: True is64bit: True
Windows-10-10.0.17763-SP0 Windows ('64bit', 'WindowsPE')
('Windows', '10', '10.0.17763')
Python 2.7.15+
Windows: ('10', '10.0.17763', 'SP0', u'Multiprocessor Free')
Interface language: None
Successfully initialized third party plugins: Gather KFX-ZIP (from KFX Input) (1, 12, 1) && DeDRM (6, 5, 3) && Package KFX (from KFX Input) (1, 12, 1) && Obok DeDRM (6, 5, 3) && EpubSplit (2, 6, 0) && KFX metadata reader (from KFX Input) (1, 12, 1) && KFX Input (1, 12, 1)
Traceback (most recent call last):
File "site-packages\calibre\gui2\actions\view.py", line 106, in view_format_by_id
File "site-packages\calibre\gui2\actions\view.py", line 155, in _view_file
File "site-packages\calibre\gui2\actions\view.py", line 125, in _launch_viewer
File "site-packages\calibre\gui2\jobs.py", line 284, in launch_gui_app
File "site-packages\calibre\utils\ipc\server.py", line 247, in run_job
File "site-packages\calibre\utils\ipc\server.py", line 220, in launch_worker
CriticalError: Failed to launch worker process:
Traceback (most recent call last):
File "site-packages\calibre\utils\ipc\server.py", line 230, in do_launch
File "site-packages\calibre\utils\ipc\__init__.py", line 22, in eintr_retry_call
File "multiprocessing\connection.py", line 147, in accept
File "multiprocessing\connection.py", line 420, in deliver_challenge
IOError: [Errno 232] The pipe is being closed

In order to open another book I have to shut down the program and then reopen it, but then I can only open one before I get the error message.

Any suggestions or advice would be greatly appreciated. Thanks

[theducks]

39 seems to have (other?) problems. There is now a 39.1

I suggest you uninstall and put 38.1 back for now.
Your libray and settings are preserved (but backups never hurt )

[tdeboor]

Thanks. I uninstalled 39.1 and reinstalled 38.1. As soon as I opened it up my library was there and I am able to open as many books as I want. Problem solved. Thanks again.

[kovidgoyal]

Something on your computer is blocking calibre from alunching its worker processes, most likely an antivirus. Exclude calibre from it and you should be fine.