[Help] Calibre 4.X eBook Viewer Broken

[Hakarune]

So I updated to the newest version tonight 4.14.0 and the ebook viewer wouldn't work. It'd come up and then be listed as not responding and on trying to close it says "calibre-parallel.exe" not working. I reverted back to 3.48.0 and the viewer works just fine. How can I fix this? This is just the app, no book even opening, just trying to open the ebook viewer crashes.

I know it's not a computer limitation because it has some great hardware that's fresh bought in the last couple months and single core speeds are great as well. on 3.x book opens instantly, 4.x nothing and crash.

[Hakarune]

Is there anyone who can help with this?

[BetterRed]

Try turning of your antivirus software.

Which OS are you using, and how are you starting the viewer?

BR

[Hakarune]

Originally Posted by BetterRed

Try turning of your antivirus software.

Which OS are you using, and how are you starting the viewer?

BR

Windows 10

No antivirus (just built-in windows defender); I tried turning it off and still didn't work, though this should never be a solution.

I've tried via Calibre opening a book, opening a book with explorer, tried going through the start menu and tried going directly to where the exe is and opening from there.

Calibre 3.x works 100% without issue. So there's something changed in the code of 4 that is causing issues.

[Uncle Robin]

Originally Posted by Hakarune

Windows 10

No antivirus (just built-in windows defender); I tried turning it off and still didn't work, though this should never be a solution.

I've tried via Calibre opening a book, opening a book with explorer, tried going through the start menu and tried going directly to where the exe is and opening from there.

Calibre 3.x works 100% without issue. So there's something changed in the code of 4 that is causing issues.

I'm running Win 10 64 Pro, also with only Windows Defender running and Calibre 4.14 viewer works just fine for me, as it is has for every iteration of 4.x

[kovidgoyal]

Here are the things you can try:

1) Update your graphics drivers
2) Run in Safe Mode
3) Turn of hardware acceleration for Qt WebEngine asdescribed here: https://doc.qt.io/qt-5/qtwebengine-debugging.html

[Hakarune]

Bug is still persistent even with changes made.

I got it to only open by itself from the programs folder after disabling hardware acceleration, but it still won't open from calibre itself.

If it's a Radeon graphics driver problem, does anyone know if it will be later addressed or is this a permanent change & Windows OS no longer a target for the program? My Radeon 560 isn't that old and the driver is fairly new as well and disabling system-wide hardware acceleration for all QTWebengine is very extreme to get only a partial fix or full fix for a single program and it impacts every other application that uses it without issue.

Why was the reader even changed to QT engine and so drastically altered?

[Hakarune]

Originally Posted by kovidgoyal

Here are the things you can try:

1) Update your graphics drivers
2) Run in Safe Mode
3) Turn of hardware acceleration for Qt WebEngine as described here: https://doc.qt.io/qt-5/qtwebengine-debugging.html

Graphics driver is the newest available, just double checked today and even tried to rollback as well, but none fixed it and disabling QT got it to finally open standalone, but won't open if launched from calibre still.

[Hakarune]

Is there a registry or app data info that needs to be cleared or something? How can I completely wipe all existence of Calibre and reinstall fresh?

[Bookstooge]

Originally Posted by Hakarune

...or is this a permanent change & Windows OS no longer a target for the program?

Hyperbole much?

[Hakarune]

Is there a registry or app data info that needs to be cleared or something? How can I completely wipe all existence of Calibre and reinstall fresh?

[BetterRed]

@Hakarune - simplest way to get a fresh calibre is to install the portable version, because it is self contained it won't use or overwrite anything from your existing install.

BR

[gbm]

Originally Posted by Hakarune

Graphics driver is the newest available, just double checked today and even tried to rollback as well, but none fixed it and disabling QT got it to finally open standalone, but won't open if launched from calibre still.

Are you using the AMD driver dated 04/23/2020 or a Microsoft driver?

bernie

[Hakarune]

Originally Posted by gbm

Are you using the AMD driver dated 04/23/2020 or a Microsoft driver?

bernie

AMD, through the Radeon Software, tried the 3 most recent version and the newest optional from like last week.

[Hakarune]

Originally Posted by Bookstooge

Hyperbole much?

No, it's a legitimate question. Especially when the solution is disable all QT hardware acceleration system wide, impacting performance of every other app that uses or could potentially use QT, or not use the program. That's an extreme "fix". If there is never going to be a fix for the issue, especially when a bug is submitted and within 24 hours is marked as invalid, then it seems like Win10 is bugs will be ignored going forward.