eBook viewer not opening in Ubuntu 20

[martinf]

Hi, have been looking for a post about this, but apparently I'm the first. Yesterday I was tweaking with folders at /etc/apt and some other stuff to solve an epson printer problem. Today calibre's eBook viewer doesn't work

I reinstalled the viewer, but still. Calibre does open all formats that I haven't selected to be opened by eBook viewer, but those that have been don't. For example pdfs are opened by the document viewer, but mobis and epubs don't open. No error message appears.

Any ideas? any libraries that I might have accidentally uninstalled that made it work?

Thanks

[martinf]

Run the calibre-debug --viewer this is what I got...

calibre-debug --viewer
Turning on automatic hidpi scaling
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 141.7674418604651 x 141.4020618556701
Using calibre Qt style: True
WebEngineContext used before QtWebEngine::initialize() or OpenGL context creation failed.
Failed to create OpenGL context for format QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples 0, swapBehavior QSurfaceFormat:efaultSwapBehavior, swapInterval 1, colorSpace QSurfaceFormat:efaultColorSpace, profile QSurfaceFormat::NoProfile)
Aborted (core dumped)

Hope this helps in helping me

Thanks

[kovidgoyal]

That's an issue with your opengl drivers, basically Qt is usable to create an OpenGL context.

[martinf]

ok, i'll check into that. Thanks for the quick reply and congratulations for the amazing work. Calibre is great!

[akikara]

Hello threre. I am using Ubuntu 22.04 latest version of Calibre 6.13

Here is my output of calibre-debug --viewer


da@ffof:~$ calibre-debug --viewer
QPA platform: xcb
devicePixelRatio: 1.0
logicalDpi: 96.0 x 96.0
physicalDpi: 92.53889943074003 x 92.67567567567568
Using calibre Qt style: True
qt.webenginecontext:

GL Type: desktop
Surface Type: OpenGL
Surface Profile: CompatibilityProfile
Surface Version: 4.3
QSG RHI Backend: OpenGL
Using Supported QSG Backend: yes
Using Software Dynamic GL: no
Using Multithreaded OpenGL: no

Init Parameters:
* application-name calibre
* browser-subprocess-path /opt/calibre/libexec/QtWebEngineProcess
* create-default-gl-context
* disable-features ConsolidatedMovementXY,InstalledApp,BackgroundFetc h,WebOTP,WebPayments,WebUSB,PictureInPicture
* disable-setuid-sandbox
* disable-speech-api
* enable-features NetworkServiceInProcess,TracingServiceInProcess
* enable-threaded-compositing
* in-process-gpu
* use-gl desktop

Problem is E-book viewer is not responding.

Here is ss:

[kovidgoyal]

Update your GPU drivers or Turn off hardware acceleration as described here: https://doc.qt.io/qt-6/qtwebengine-debugging.html