Calibre Worker Process - I found one reason why

JSWolf · 05-15-2026, 05:19 AM

I'm running Windows 11 Home.

I ran calibre and then closed it. I then checked Task Manager and no stuck processes. I then ran calibre, I viewed a book I had not viewed before in the viewer. I then closed the viewer and closed calibre. I then ran Task Manager and I had two calibre worker process tasks showing.

So something is up with the viewer. It doesn't close all the tasks.

JSWolf · 05-15-2026, 05:23 AM

I now found another source for stuck processes. I did the same thing as above. But this time with the editor and again, after calibre was closed, a stuck process was left behind.

kovidgoyal · 05-15-2026, 10:07 AM

Neither of those two scenarios leave any workerprocesses for me. I vaguely recall you turned on GPU acceleration for webengine I suggest you turn it off again.

JSWolf · 05-15-2026, 06:32 PM

Quote:

Originally Posted by kovidgoyal

Neither of those two scenarios leave any workerprocesses for me. I vaguely recall you turned on GPU acceleration for webengine I suggest you turn it off again.

Why would using the GPU leave processes behind? Can anything be done about it?

kovidgoyal · 05-15-2026, 11:26 PM

Why dont you try it and see.

05-15-2026, 05:19 AM	#1
JSWolf Resident Curmudgeon Posts: 83,504 Karma: 153646249 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	Calibre Worker Process - I found one reason why I'm running Windows 11 Home. I ran calibre and then closed it. I then checked Task Manager and no stuck processes. I then ran calibre, I viewed a book I had not viewed before in the viewer. I then closed the viewer and closed calibre. I then ran Task Manager and I had two calibre worker process tasks showing. So something is up with the viewer. It doesn't close all the tasks.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Failed to start worker process	Doum	Calibre	2	07-07-2020 05:05 AM
Newbie Winrar and Calibre Worker Process Issue	Highstreet54	Devices	2	01-04-2019 04:38 PM
Failed to connect to worker process	Frenchguy	Devices	2	08-31-2018 05:00 AM
Metadata source plugin - worker.py not found	ru_cal	Development	0	08-11-2015 10:52 AM
Failed to launch worker process	klonuo	Library Management	1	12-22-2011 04:33 AM

05-15-2026, 05:23 AM	#2
JSWolf Resident Curmudgeon Posts: 83,504 Karma: 153646249 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I now found another source for stuck processes. I did the same thing as above. But this time with the editor and again, after calibre was closed, a stuck process was left behind.

05-15-2026, 10:07 AM	#3
kovidgoyal creator of calibre Posts: 46,253 Karma: 29630732 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Neither of those two scenarios leave any workerprocesses for me. I vaguely recall you turned on GPU acceleration for webengine I suggest you turn it off again.

05-15-2026, 11:26 PM	#5
kovidgoyal creator of calibre Posts: 46,253 Karma: 29630732 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Why dont you try it and see.