User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0

Steps to reproduce:

After updating TB from 85 to 86.0b1.

Actual results:

After updating TB from 85 to 86.0b1 text in folders and message pane is blurry. Other places (menus, message compose and view window) is ok.

Expected results:

Text rendering changed - how to set those panels to display text properly?

I suspect that simply the font was changed/hardcoded - it is different now in folders and messages pane and the rest of windows. How can I set the font to these panes manually - perhaps by using .css ?

I don't think any fonts changed. Post a screen shot?

Start in safe mode? https://support.mozilla.org/en-US/kb/safe-mode-thunderbird

Her you can see font difference: https://www.xsistema.lt/file-manager/downloads/44348629-dbdd-42b6-9618-acc2a942718c_TB%2086..png

Indeed, after restarting in safe mode and with add-ons disabled, fonts are as should be.. Will try to find which add-on or .css caused the problem.

Strange, but after removing add-on, and .css (chrome folder) and restarting - fonts are still different... But restarting in safe mode helps - even when checkbox "Disable all add-ons" is unchecked.

Is it possible to change the font in folders and messages pane by using userChrome.css? That would solve the problem.

Please use "Attach new file" button (found above your first comment) to add your image to the bug report.

Messages panel font is different (the same in folders panel). See the two lines above in picture.

The switch for using hardware acceleration is turned off when you start in safe mode. Blurry fonts from having it turned on are video driver version dependant and have been around ever since video acceleration was introduced.

I would guess disabling it in option will fix the issue for you, but it will probably not do anything for those that just open the program and go "unusable" and move on.

Bug 591139 set the default state to disabled in safe mode.
Bug 1623265 reenabled the hardware acceleration for the Thunderbird 78 release series.

I am unconvinced that re-enabling a problematical default because it causes problems with automated testing is a good idea. But that is what has occurred.

Yes, I have disabled hardware acceleration and now fonts are displayed perfectly..

After update from 86.0b1 to 86.0b2 - "Use hardware acceleration.." has no effect for text rendering - font is blurry again....

In safe mode - fonts looks ok...

After update from 86.0b2 to 86.0b3 font rendering is ok again (no more damage to my eyes - I hope not just mine..).

After update from 86.0b3 to 87.0b1 fonts are blurry again (damage to my eyes - I hope not just mine..). What's going on with TB?? Hardware acceleration does not he,p - ON/OFF. In safe mode - ... now even can not start in safe mode from Help -> Restart in safe mode - Error console log:

Prompter: internal dialogs not available in this context. Falling back to window prompt. Prompter.jsm:1033
set modalType resource://gre/modules/Prompter.jsm:1033
ModalPrompter resource://gre/modules/Prompter.jsm:989
pickPrompter resource://gre/modules/Prompter.jsm:44
confirmEx resource://gre/modules/Prompter.jsm:304
safeModeRestart chrome://messenger/content/mailCore.js:783
oncommand chrome://messenger/content/messenger.xhtml:1
Uncaught TypeError: BrowserUtils.restartApplication is not a function
safeModeRestart chrome://messenger/content/mailCore.js:802
oncommand chrome://messenger/content/messenger.xhtml:1
mailCore.js:802:18
safeModeRestart chrome://messenger/content/mailCore.js:802
oncommand chrome://messenger/content/messenger.xhtml:1

Update to 87.0b2 (64-bit) - still blurry fonts.......... this makes me crazy.. Starting to thinking about switching to some other mail software... This is similar like Skype was ruined after MS bought it from eBay. Also - can not start TB in safe mode any more....

Also - every time TB is launched - it asks to confirm to set it as default..

Update to 87.0b3 (64-bit) - still blurry fonts - can not restart in safe mode... Problems, problems..

Just leave hardware acceleration disabled, as you stated in comment 10.

This is in core code, so it isn't something Thunderbird can fix. And with different rendering code coming in future versions I doubt anyone will put effort into fixing the current issue.

Hardware acceleration - disabled - fixed the problem in this version - 87.0b3 (64-bit) - I can see clear text again. Hope this feature will stay untouched / working.. But still - can not restart with Add-ons disabled.

Update to 88.0b1 (64-bit) - blurry fonts again - in safe mode ok. Hardware acceleration setting does not help. How can I control folder pane fonts with css? What are the properties names? I would try to experiment with those properties.

Update to 88.0b2 (64-bit) - blurry fonts again - in troubleshoot mode ok. Not in troubleshoot mode with add-ons disabled - fonts are blurry... Also - when new message popup window shows - and after clicking the link (message title) - the focus is not transferred to TB - link not working... Bad bad, what's going on with TB? The last few months only troubles... Staff changed?

As you are testing out the beta versions to help to reveal gremlins, your efforts really are appreciated.
But, I'm not seeing a load of people reporting this particular issue, so can you see if the following offers some help and report back on the results.
Just for the record - what graphics card is computer using?
Can you confirm you have updated your computer graphics card to use the latest available?

Can you also confirm whether you have tried using the computer compatibility troubleshooting method ?

Right click on the Thunderbird shortcut icon and select Troubleshoot compatibility.
Or right click on the thunderbird shortcut icon and choose 'Properties' then under the 'Compatibility' tab use the 'Run compatibility troubleshooter'.

It's Intel UHD Graphics P630 with latest driver. I have tried troubleshooting mode - please read my previous message. Perhaps this will help - I'm using Tahoma system font (not ugly Segoe UI).

Like I mentioned - ONLY folder and message list panel is affected. In other places (menus, message panel, etc.) fonts ok, not blurry. I suspect that somehow font family may be changed (hardcoded?) on folders and message list panel? Just for reference - if I change system font to SegoeUI - text is blurry, but with Tahoma - text is sharp as should be.

Update to 89.0b3 - still blurry fonts. In safe mode - OK.

(In reply to Ernestas Gruodis from comment #25)

Update to 89.0b3 - still blurry fonts. In safe mode - OK.

But you do not mention whether hardware acceration was enabled or not in normal mode. It is auto disabled in Safe Mode, which probably explains why it works in Safe Mode.

Are you finding that hardware acceleration is being auto enabled each time you update and you need to uncheck that option and restart after each update in order to fix? In which case, the issue is why is it being auto enabled when that setting was disabled.
I am presuming you are not enabling the option to use hardware acceleration.
Please confirm you are not changing the option to use hardware acceleration; you disabled it and never switched it on. That it is being auto switched on after each update.

At this point, if the hardware acceleration is repeatedly being auto set as enabled, can you check the following as I have come across weirdness before where an unused profile was effecting used profiles. I would like to either confirm or rule out this.

In the Thunderbird/'Profiles' folder - Do you have another profile name folder which you do not use ?
If yes:
You could either delete that unused profile if you are sure you never use it. If deleting, please use the 'Profile Manager' to ensure it is properly removed.

OR you could keep it and edit the prefs.js file as follows to see if the other unused profile is somehow causing a conflict.
It would be useful to know if this was true.

Make sure the current profile you are using has hardware acceleration disabled.
Exit Thunderbird.

Access profile name folder you do NOT use.
Open 'prefs.js' using a text editor
scroll down to locate this line: user_pref("gfx.direct3d.last_used_feature_level_idx", 0);
create a new line above that line.
Enter the following: user_pref("gfx.direct2d.disabled", true);

so you know have in the following order
user_pref("gfx.direct2d.disabled", true);
user_pref("gfx.direct3d.last_used_feature_level_idx", 0);
Save the prefs.js file.

Start Thunderbird.

(In reply to Anje from comment #26)

(In reply to Ernestas Gruodis from comment #25)

Update to 89.0b3 - still blurry fonts. In safe mode - OK.

But you do not mention whether hardware acceration was enabled or not in normal mode. It is auto disabled in Safe Mode, which probably explains why it works in Safe Mode.

Are you finding that hardware acceleration is being auto enabled each time you update and you need to uncheck that option and restart after each update in order to fix? In which case, the issue is why is it being auto enabled when that setting was disabled.
I am presuming you are not enabling the option to use hardware acceleration.
Please confirm you are not changing the option to use hardware acceleration; you disabled it and never switched it on. That it is being auto switched on after each update.

Hardware acceleration is switched off (tried on or off - no difference).

(In reply to Anje from comment #27)

At this point, if the hardware acceleration is repeatedly being auto set as enabled, can you check the following as I have come across weirdness before where an unused profile was effecting used profiles. I would like to either confirm or rule out this.

In the Thunderbird/'Profiles' folder - Do you have another profile name folder which you do not use ?
If yes:
You could either delete that unused profile if you are sure you never use it. If deleting, please use the 'Profile Manager' to ensure it is properly removed.

OR you could keep it and edit the prefs.js file as follows to see if the other unused profile is somehow causing a conflict.
It would be useful to know if this was true.

Make sure the current profile you are using has hardware acceleration disabled.
Exit Thunderbird.

Access profile name folder you do NOT use.
Open 'prefs.js' using a text editor
scroll down to locate this line: user_pref("gfx.direct3d.last_used_feature_level_idx", 0);
create a new line above that line.
Enter the following: user_pref("gfx.direct2d.disabled", true);

so you know have in the following order
user_pref("gfx.direct2d.disabled", true);
user_pref("gfx.direct3d.last_used_feature_level_idx", 0);
Save the prefs.js file.

Start Thunderbird.

Only default profile exists..

Finally - found the solution - setting gfx.webrender.force-disabled to true - fixes the issue. What will be the next steps? Is there some bug?

What will be the next steps? Is there some bug?

This depends on your webrender bug 1689845. In beta, webrender in some cases which replaces the current graphics code.

Gut feeling (reading from the perspective of a user of Firefox on (Tier-3) FreeBSD):

• wonder whether the issue is more with a font (or combination of fonts), than with Thunderbird.

In an ideal world, I'd like to know whether symptoms are reproducible with Thunderbird alone added to a fresh installation of Windows 10.

Then (re: comment #24) tell whether symptoms are reproducible with a change to preferences for fonts (without installing any additional font).

whether symptoms are reproducible with Thunderbird alone added to a fresh installation of Windows 10.

I meant to say … whether symptoms are reproducible with Thunderbird alone added to a fresh installation of Windows 10 on an identically-specified computer.

Setting gfx.webrender.force-disabled to true does not help anymore on TB 92.0b1... Font is blurry again..

The same on Mozilla Firefox 92.0b3 (on 91 was ok). It means gfx.webrender.force-disabled option removed?

But found another solution - by setting gfx.webrender.blob-images to false solves the problem. How can it be related?

(In reply to Ernestas Gruodis from comment #23)

… Intel UHD Graphics P630 with latest driver. …

Which version, specifically?

Does Intel DSA find anything applicable?

(In reply to Ernestas Gruodis from comment #0)

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:86.0) Gecko/20100101 Firefox/86.0

With the following, no problem:

• FreeBSD
• Thunderbird 78.13.0 build 20210805110815
• gfx.webrender.enabled overridden to true (enough for about:support to show WebRender in lieu of Basic for compositing)
• gfx.webrender.all overridden to true
• sans serif for proportional
• defaults for serif, sans-serif and monospace (respectively: DejaVu Serif, DejaVu Sans, DejaVu Mono)
• Victor Mono preferred in the Fonts pane of System Settings (KDE Plasma)
• ClassicLooks http://www.itgroup.ro/WSX/wsx_content/en/linux/classiclooks.html
• AMD Thames [Radeon HD 7550M/7570M/7650M] driven by radeonkms

% pkg info -x thunderbird
thunderbird-78.13.0
% uname -KUv
FreeBSD 14.0-CURRENT #105 main-n248685-c9f833abf1d: Fri Aug 13 20:24:43 BST 2021     root@mowa219-gjp4-zbook-freebsd:/usr/obj/usr/src/amd64.amd64/sys/GENERIC-NODEBUG  1400030 1400030
% sysrc kld_list
kld_list: fusefs usbhid drm
% 

(In reply to Ernestas Gruodis from comment #35)

The same on Mozilla Firefox 92.0b3 (on 91 was ok). It means gfx.webrender.force-disabled option removed?

If I'm not wrong the pref has changed to gfx.webrender.enabled. When FX is affected then you should open a dedicated FX bug with examples in FX.
TB is only a customer of toolkit and we can't do anything.

(In reply to Richard Marti (:Paenglab) from comment #38)

(In reply to Ernestas Gruodis from comment #35)

The same on Mozilla Firefox 92.0b3 (on 91 was ok). It means gfx.webrender.force-disabled option removed?

If I'm not wrong the pref has changed to gfx.webrender.enabled.

Emilio, do both preferences work in version 91 esr?

(In reply to Ernestas Gruodis from comment #36)

But found another solution - by setting gfx.webrender.blob-images to false solves the problem. How can it be related?

Does this make sense? And along those lines, is there any webrender "sub" preference that could help bug 1697999? (i.e. short of fully disabling webrender)

(In reply to Wayne Mery (:wsmwk) from comment #39)

(In reply to Richard Marti (:Paenglab) from comment #38)

(In reply to Ernestas Gruodis from comment #35)

The same on Mozilla Firefox 92.0b3 (on 91 was ok). It means gfx.webrender.force-disabled option removed?

If I'm not wrong the pref has changed to gfx.webrender.enabled.

Emilio, do both preferences work in version 91 esr?

gfx.webrender.enabled should be used to opt into webrender, but it being false doesn't mean you don't get webrender. The force-disabled pref should work on ESR.

(In reply to Ernestas Gruodis from comment #36)

But found another solution - by setting gfx.webrender.blob-images to false solves the problem. How can it be related?

Does this make sense?

Not sure, I'd ask Lee / Nical.

And along those lines, is there any webrender "sub" preference that could help bug 1697999? (i.e. short of fully disabling webrender)

I don't think so...

The Support Forum has a report of blurry text when using Win10x64, TB v91.1.2 x64
https://support.mozilla.org/en-US/questions/1352219

Updated from latest v7*, to v91.1.2
text for the items [ account names, folder names, ..] and titles of the listed emails got blurry.
Before update, on v7* text was sharp, and after updated change happened after restart for the completing the update.
troubleshoot mode text is sharp again
HW accel. disabled - does not helps, still blurry
No add-ons using, TB vanilla.

Found this: https://www.ghacks.net/2021/08/27/mozilla-plans-to-enable-webrender-in-firefox-92/

From Firefox 93 onward, Firefox users can't disable WebRender anymore as options to do so are no longer included in that version of the web browser. The only option that Firefox users have when they encounter rendering issues is to switch WebRender to software.

Firefox intention to remove the ability to switch webrendering off and user would need to switch on gfx.webrender.software
Would this information be relevant to Thunderbird for this blurry text bug ?
In v 91.1.2 There is already preference 'gfx.webrender.software' set to false by default.

Does setting this to true fix blurry text ?

(In reply to Ernestas Gruodis from comment #5)

Strange, but after removing add-on, and .css (chrome folder) and restarting - fonts are still different... But restarting in safe mode helps - even when checkbox "Disable all add-ons" is unchecked.

Hi Ernestas, the checkbox Disable all add-ons is only about making that change the new default for your install (even when you're no longer in TS mode). So even if you don't check it and enter TS mode, add-ons will still be temporarily disabled. I've always found this dialog confusing, but not sure how to improve it. One improvement I've suggested is bug 1726817.

some additional examples

I encounter this bug since updating to 91.2.1 bug, too. If I restart in safe mode, the problem is solved. How can I fix it permanently?

PS: Disabling add-ons doesn't make a difference.

gfx.webrender.force-disabled is still there, but changing it doesn't make a difference.

gfx.webrender.blob-images set to false fixes the problem, woohoo! Thanks Ernestas.

I'll disable automatic updates of Thunderbird for the future as this bug cost me around 3 hours of my life. Thanks.

One thing safe-mode disables is hardware acceleration. You can try disabling this in the Thunderbird preferences and see it if helps.

Thanks, but unfortunately it doesn't help.

Maybe you had used a userContent.css or userChrome.css?
Not sure what else it could be. Tried creating a new profile? (thunderbird.exe -P)

Like I wrote, the issue has been fixed - for now - with this:

"gfx.webrender.blob-images set to false fixes the problem, woohoo! Thanks Ernestas."

However, the bug was introduced simply by (automatically) updating from 78.14.0 to 91.2.1. I didn't change anything and I don't have used userContent.css or userChrome.css.

Someone in charge should fix this bug once and for all.

Thanks!

I think that preference was introduced in Firefox 60 and is shared code with Thunderbird.

See WebRender: Blob Images

Bug 1362115 - [meta] Turn on gfx.webrender.blob-images (blob images) by default

See also 635490. Can't add that above for some reason.

Probably bug 1732965