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