Preview failure

[Glennfrancis]

Running Sigil 2.3.0 on an old, but up to date Windows 10 PC, and when I try to open the Sigil User Guide (for example; I assume this will run in Sigil…seems like a reasonable assumption/test case) the Preview window will very briefly display an item, like the cover, when the Update Preview Window button is pressed, but only for a single second. Same goes for any other content from the User Guide: appears for a second in the Preview window, and then vanishes.
Any other doc I’ve loaded (like the book I’m working on, which displays a TOC just fine) I have no preview at all of. I’ve searched high and low for a clue about what’s going on, but no joy. Am I simply doing something dumb that’s causing this?

[BetterRed]

Working fine here: Sigil 2.3.0 Win 10.

Which version of the User Guide? Latest is here ==> Sigil User Guide - Sigil-Ebook

BR

[DiapDealer]

Try ticking the box in Sigil's preferences to disable hardware acceleration in Qt/WebEngine. The guide has tons of images and has embedded fonts. Aging hardware and the newer Qt6 in Sigil 2.3.0 are likely combining to cause problems.

[Glennfrancis]

Thanks. Made the preferences change, but the problem persists after restart. I would prefer that “aging hardware,” much as it makes sense, not be the only remaining diagnosis; any other ideas?

[KevinH]

You may have an anti-virus program that is interfering with the QWebEngineProcess application that runs behind the scenes.

You may have a firewall setting that interferes with even local sockets to prevent inter-process communications.

You may have an unsupported graphics driver. Have you tried updating to the very latest driver for your graphics card?

Fire up Sigil and load the Users Guide and navigate to any page. Even if Preview is blank, try hitting the Inspector button on the Preview Toolbar. Does the Inspector open? Can you see anything? If so, look at the source code via Preview's Inspector, Does it look similar to what CodeView is showing (after uncollapsing the code whereneeded).

It you see it just for a flash and it goes away, then something is interfering with Qt's QWebEngine, most probably really misguided anti-virus software.

Perhaps your aging processor does not support AVX or other advanced registers required?

[DiapDealer]

After eliminating anti-virus as the culprit, try creating an environment variable named QSG_RHI_BACKEND and setting its value to "opengl" (no quotes), and then launch Sigil. This should eliminate the possibility that your d3d11 (now the default) implementation is not quite up to snuff by forcing all QtQuick stuff to use opengl instead.

[KevinH]

And then there is this bug related to CPUs without AVX and SSE4 which causes the QtWebEngine render process to crash.

https://bugreports.qt.io/browse/QTBUG-123811

So does your older hardware cpu support AVX and SSE4?

[DiapDealer]

Anything new on this front?

[JSWolf]

Could the preview problem maybe be related to the graphics driver?

[DNSB]

Originally Posted by JSWolf

Could the preview problem maybe be related to the graphics driver?

Please see message #5 in this thread.

[Glennfrancis]

Thanks for your help, everybody: much appreciated. systeminfo tells me my processor is from 2008, so I imagine it lacks lots of bells and whistles. Graphics driver duly updated. I run standard Windows Security, with Defender Firewall standard-issue, but as far as I can tell (which is not very far...) anything like "Sigil" has not been blocked. Even looking for that is the far edge of my tech skills, so the more advanced suggestion from DD is beyond my pay grade, so to speak. I might have to await a newer machine before I can do more with this installation: I don't know what I don't know, so questions about the capability (or not) of my hardware are a bit beyond me. And, I'm grateful for the help.

[DiapDealer]

Definitely give that environment variable I mentioned in post #6 a shot. You may want to reboot after setting it to make sure it's "live". If you need help setting an environment variable, just ask.

EDIT: Sorry. Just noticed the part where you said my suggestion might be above your tech pay grade. I'll leave some instructions just in case you're ever feeling adventurous.

1) type "env" (without the quotes) in your search box on your taskbar.
2) click the "Edit the system environment variables" link that appears in the right hand column of the popup window.
3) look for the "Environment Variables" button near the bottom of the ensuing dialog and click it.
4) in the top half of the next dialog (User variables), click the "New" button.
5) in the "Variable name" box, type: QSG_RHI_BACKEND
6) in the "Variable value" box, type: "opengl" (without the quotes); and then click the "OK" button.
7) click the OK button on the Environment Variables dialog.
8) and finally click the OK button on the System Properties dialog.
9) reboot to be safe and try running Sigil again.