Viewer not opening any ebooks

jenrar · 12-04-2025, 07:25 PM

Most of the time, my Viewer won't open a book. First open or not. Occasionally it works fine for a whole session of me opening books (to verify name on cover, read, whatever). But then I go for a while and it doesn't work. Opening it just sits there and "spins" (ie loads).

I've done searches here. I know that it might be a cache problem. But I am absolutely clueless about how to do the suggested move of the cache if that's what's needed.

theducks · 12-04-2025, 07:29 PM

Most common is the Graphics driver on the PC is old. Try for an updated driver.

(I have one that is so ancient and no updates. Last Calibre VIEWER that worked was 7.16. Main Calibre did still function)

jenrar · 12-04-2025, 07:32 PM

Okay, I just tried updating but it says I have the latest updates. All my PC updates are up-to-date, including the graphics driver.

Quote:

Originally Posted by theducks

Most common is the Graphics driver on the PC is old. Try for an updated driver.

(I have one that is so ancient and no updates. Last Calibre VIEWER that worked was 7.16. Main Calibre did still function)

jenrar · 12-07-2025, 05:26 PM

So no one else having that issue or thoughts on it?

kovidgoyal · 12-07-2025, 10:09 PM

First, try rebooting in safe mode and see if it works.

jenrar · 12-07-2025, 11:29 PM

That worked! Yay. Even better, rebooted in regular mode, and they open perfectly, even ones I haven't opened before. Double yay!

But...what does that mean? LOL

At least now I know what to do if it happens again.

Thanks, kovidgoyal!

Quote:

Originally Posted by kovidgoyal

First, try rebooting in safe mode and see if it works.

kovidgoyal · 12-08-2025, 12:46 AM

It means there is some software on your computer that is interfering with calibre, typical culprits are anti virus or file sync programs.

jenrar · 12-08-2025, 01:03 AM

Hmm. Okay. Thank you.

Quote:

Originally Posted by kovidgoyal

It means there is some software on your computer that is interfering with calibre, typical culprits are anti virus or file sync programs.

jenrar · Yesterday, 02:50 PM

I don't know what to do. When they stopped opening again, I closed all open programs, tried opening a book, and still it won't open.

I don't have any antivirus, any firewall, any sync programs open.

Quote:

Originally Posted by kovidgoyal

It means there is some software on your computer that is interfering with calibre, typical culprits are anti virus or file sync programs.

BetterRed · Yesterday, 04:00 PM

Post a screenshot of your Task manager->Start up tab, maybe someone can suggest the culprit.

Alternatively, after disabling everything in that list, do a restart to see if the problem has gone away. If so, work through the list methodically enabling individual startup tasks and doing a restart.

BR

jenrar · Yesterday, 04:10 PM

https://i.ibb.co/TBwTm6fJ/1.png

https://i.ibb.co/JRhzr1kT/2.png

BetterRed · Yesterday, 05:15 PM

I can't see those screen shots:

Click image for larger version

Name: Screenshot 2025-12-11 080846.jpg
Views: 5
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ID: 219671

Post them here, you can do that via the paper clip icon on the top row of the Advanced mode toolbar:

Click image for larger version

Name: Screenshot 2025-12-11 081216.jpg
Views: 4
Size: 103.3 KB
ID: 219674

BR

jenrar · Yesterday, 05:20 PM

Oh, sorry.

Click image for larger version

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ID: 219675

Click image for larger version

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ID: 219676

Quote:

Originally Posted by BetterRed

I can't see those screen shots:

Attachment 219671

Post them here, you can do that via the paper clip icon on the top row of the Advanced mode toolbar:

Attachment 219674

BR

JSWolf · Yesterday, 05:23 PM

Quote:

Originally Posted by jenrar

Oh, sorry.

Attachment 219675

Attachment 219676

Disable everything in Startup and reboot. Then try calibre again and see if it works. If it works, it's something you run at start.

Are you on a laptop with dual video chipsets? If so, before doing the above suggestion, have calibre run with the other GPU it's not currently running with. If that and the above suggestion fails, add the following environment variable and reboot.

Code:

QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu

BetterRed · Yesterday, 05:47 PM

Quote:

Originally Posted by JSWolf

Disable everything in Startup and reboot. Then try calibre again and see if it works. If it works, it's something you run at start.

Are you on a laptop with dual video chipsets? If so, before doing the above suggestion, have calibre run with the other GPU it's not currently running with. If that and the above suggestion fails, add the following environment variable and reboot.

Code:

QTWEBENGINE_CHROMIUM_FLAGS=--disable-gpu

↑ ↑ ↑ ✔

BR

12-04-2025, 07:25 PM	#1
jenrar Connoisseur Posts: 83 Karma: 10 Join Date: Nov 2011 Device: none	Viewer not opening any ebooks Most of the time, my Viewer won't open a book. First open or not. Occasionally it works fine for a whole session of me opening books (to verify name on cover, read, whatever). But then I go for a while and it doesn't work. Opening it just sits there and "spins" (ie loads). I've done searches here. I know that it might be a cache problem. But I am absolutely clueless about how to do the suggested move of the cache if that's what's needed.

Yesterday, 04:00 PM	#10
BetterRed null operator (he/him) Posts: 22,064 Karma: 30277960 Join Date: Mar 2012 Location: Sydney Australia Device: none	Post a screenshot of your Task manager->Start up tab, maybe someone can suggest the culprit. Alternatively, after disabling everything in that list, do a restart to see if the problem has gone away. If so, work through the list methodically enabling individual startup tasks and doing a restart. BR Last edited by BetterRed; Yesterday at 04:02 PM.

Yesterday, 05:15 PM	#12
BetterRed null operator (he/him) Posts: 22,064 Karma: 30277960 Join Date: Mar 2012 Location: Sydney Australia Device: none	I can't see those screen shots: Post them here, you can do that via the paper clip icon on the top row of the Advanced mode toolbar: BR

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12-04-2025, 07:29 PM	#2
theducks Well trained by Cats Posts: 31,343 Karma: 62025226 Join Date: Aug 2009 Location: The Central Coast of California Device: Kobo Libra2,Kobo Aura2v1, K4NT(Fixed: New Bat.), Galaxy Tab A	Most common is the Graphics driver on the PC is old. Try for an updated driver. (I have one that is so ancient and no updates. Last Calibre VIEWER that worked was 7.16. Main Calibre did still function)

12-07-2025, 05:26 PM	#4
jenrar Connoisseur Posts: 83 Karma: 10 Join Date: Nov 2011 Device: none	So no one else having that issue or thoughts on it?

12-07-2025, 10:09 PM	#5
kovidgoyal creator of calibre Posts: 45,701 Karma: 28549304 Join Date: Oct 2006 Location: Mumbai, India Device: Various	First, try rebooting in safe mode and see if it works.

12-08-2025, 12:46 AM	#7
kovidgoyal creator of calibre Posts: 45,701 Karma: 28549304 Join Date: Oct 2006 Location: Mumbai, India Device: Various	It means there is some software on your computer that is interfering with calibre, typical culprits are anti virus or file sync programs.

Yesterday, 04:10 PM	#11
jenrar Connoisseur Posts: 83 Karma: 10 Join Date: Nov 2011 Device: none	https://i.ibb.co/TBwTm6fJ/1.png https://i.ibb.co/JRhzr1kT/2.png