[DESKTOP] Font Error?

[GregM]

On my new/old 18.04 computer (Optiplex 990) I get strange artifacts when I am typing specially on some web-pages like Facebook.
I've taken a snapshot and blown it up a bit so it's easier to see.
Most of the times it looks like little "J"s have been inserted in to words. In this case it is not something I have written but sometimes it is.
Is this a hardware issue, display card etc or a software issue?
Here's what it looks like...

[oshunluvr]

Looks like a video buffer corruption, likely a driver issue - possible failing video RAM, but less likely.

Video card and driver version would be the minimum requirements to begin trouble shooting something like this.

I assume you started at the simplest place first and re-seated your video cable(s) and video card if it's stand-alone?

[GregM]

Haven't done a thing yet.
It's a brand new card that I got for this computer build for 18.04.
It does not do that on all posts or writings, just some.

[claydoh]

Still, what card/ driver?

[GregM]

An Asus Radeon R5 230 2gb

[claydoh]

oops I forgot to ask which browser as well

If is Chrome, you can try choosing different fonts in the settings, I assume the same for firefox, but I think Chrome may have different fonts than FF
There are many factors that can affect this, we've eliminated the Nvidia card/driver combo possibility
But the screen size and resolution, and the antialiasing settings all can mess with this.
Is the resolution set to your monitor's default? Any monitor scaling settings changed? Have you logged out since the last batch of updates? Does this happen in other browsers?

If everything else on your screen looks good all the time, and the resolution is the screen's native one, I would start with the browser's font settings and play with those

[GregM]

oops I forgot to ask which browser as well

If is Chrome, you can try choosing different fonts in the settings, I assume the same for firefox, but I think Chrome may have different fonts than FF
There are many factors that can affect this, we've eliminated the Nvidia card/driver combo possibility
But the screen size and resolution, and the antialiasing settings all can mess with this.
Is the resolution set to your monitor's default? Any monitor scaling settings changed? Have you logged out since the last batch of updates? Does this happen in other browsers?

If everything else on your screen looks good all the time, and the resolution is the screen's native one, I would start with the browser's font settings and play with those

Firefox 56
I have it hooked up via an analog plug maybe I'll try the digital side.
Yes native rez.
Have not tried any other browsers on this computer. (Don't have any)
This is the computer that also has a Win7 hdrive and when I boot from that drive I have not noticed this problem.

[GregM]

Tried the digital side on the Radeon and it was worse (ugly).
Tried a different graphics card and it has the same issue.
Tried the onboard graphics adapter and it has the same issue.
Tried a different monitor and it has the same issue.

I guess it's got to be some display/software issue with 18.04. I don't have problems with 16.04 or Win7.
Can't think of anything else.

Couldn't be a ram issue could it? I don't have the max ram installed on the 18.04 computer.

[Goeroeboeroe]

Firefox and Chrome use the same fonts, because it's the website that determines what fonts to use. If you change the fonts in the settings, that has almost always no effect at all. As soon as a website chooses a font, that overrides the settings. Almost every site says what fonts to use, and only when that font isn't installed on your computer and is also not downloaded, then the fonts in the settings will be used.
(There are ways to force using a certain font, but they are pretty complicated.)

I know almost nothing about graphical cards etc., so maybe what I write below is all nonsense.

The first simple thing to do: clear the cache from Firefox. More and more sites make you downloading fonts, and maybe such a font is damaged. (A site first looks if you have the font downloaded before. If so, the site uses that already downloaded font.)
I have a Dutch Firefox, so maybe some English words are a bit different.
Go in Firefox to Settings -> Privacy & Security.
Go to the heading Cookies and websitedata
Click on the first line under that heading: delete data
A window opens. Check ONLY the SECOND line: Buffered Webdata (... MB)
(If the first line is checked, uncheck that. I wonder what eh, clever person at Mozilla put that line first...)
Reload the site with Shift + F5. If there was a corrupt downloaded font, it will be replaced. (And your problem is solved and I am a hero, so this simply method probably will not work.)

Since it happens only on some sites, I wonder if it can be a corrupt font? Or maybe with some exotic css a site uses (like some obscure font-feature-setting) Firefox can't handle, possibly in combination with one or more fonts.
If you want to be sure it has nothing to do with Firefox (or a font / css property) you could look what font is used on sites you have the problem. If you press in Firefox on F12, you open developer tools. On the upper left is a square with an arrow in it. If you click that square, and after that you click on the textfield you have the problem, you can find the font the site uses. Be sure to click exactly in the textfield.
After this clicking, in the right column from developer tools you can find the font that's used. You probably see a whole lot of lines there, but if you scroll through them sooner or later you'll find a line that starts with 'font' or 'font-family'. Maybe you see more lines starting with that. Some of these lines will have a strikethrough (I mean a line through the rule, but I don't know how to describe that in decent English...)
In front of every line there's a little square with a checkmark. If you click on that checkmark, you disable that line.

You have to disable all lines starting with 'font' or 'font-family', because if you disable only one, the next rule takes over.
After unchecking all that lines you are sure to use a font that's installed in your computer. If you have choosen a standard font in the settings of Firefox (or use the standard standard font Firefox automatically chooses) that font will now be used. If you now still have the problem, then it's almost sure it has nothing to do with the site or the browser. If the problem is solved, it may have something to do with a bug in Firefox or something like that.

Typing here in this very textfield if I uncheck that lines, I can see the font changing (to a very ugly system font...)
You can try this trick in the textfield where you have the problem. If you remove the checkmarks, the font is live changed. If it has to do with a certain font, the problem will probably disappear. If the problem still persists, it probably has nothing to do with browser or font. (Or a combination of the two.)

If it's working okay after removing that checkmarks, can you give a link to a site where the problem is? I've seen very strange bugs, like in Chrome a totally wrong width when you used the rarely used ch as unit, but only in one specific font. That was an error in the description of the font.
If I look at your picture, it looks like almost every 'j' comes after a letter with a round 'belly' like o or b. And most points come are after a h. It looks like the description of the font tries to change the space between two combinations of letters, but instead of changing the space you see the commands. Or something like that.
As far as I know it's the font together with the browser that are responsible for that kind of commands.

[GregM]

Thanks I'll give that a try.
Cross your fingers

[GregM]

I followed your instructions and unchecking the box seems to have cured the issue.
Here's a photo of that listing.



Next I'll try to follow your instructions on reloading that font.
Thank you this is very encouraging.

[Goeroeboeroe]

That's really strange.
font-family: Helvetica, Arial, sans-serif is a very common combination, because (almost) every system has Arial or Helvetica installed.
On my Ubuntu 15.04 Arial is installed.
(The rule means: use Helvetica. If that's not installed: use Arial. If that's also not installed, use a font without serifs (little lines at the end of the letters). Maybe I write too detailed, but I don't know how much you know about this stuff.)
So Firefox is probably using one of your own fonts, probably Arial. In that case reloading the font has no effect, because the font is never downloaded, since it's already installed on your system.

I really don't understand how unchecking that mark can make a change, because you are probably still using the same font.
O no, wait. Maybe that's not the case any more.

First: are you sure you unchecked ALL lines starting with font or font-family? (On top of the right column of developer tools there's a little text field with 'Filter styles' in it (or something like that). If you type 'font' in there, you'll only see rules with font in it.)

Second: if I look in the settings of my Firefox, the default font is DejaVu Serif. If I uncheck all font-rules, that's the font that's used by my Firefox.
You could have a look at your Firefox-settings to see what's your standard font. (Settings first page under heading Fonts & colors, or something like that.)
Or as an alternative: if you have unchecked ALL rules with font / font-family, in the right column of developer tools there's a tab 'Font' on the right. If you click on that tab, you can see which fonts the page uses. If you unchecked all font-fules, you'll only see the standard fonts Firefox chooses. In my system that are DejaVu Sans/Oblique/Bold and Verdana.

In both ways you’ll find name(s) of the font(s) in use by Firefox. If that's not Arial or Helvetica, and the problem is gone, that’s an indication there may be something wrong with your Arial or Helvetica. But I've no idea how to check that, or how to reinstall that. That's something for people that know more about Linux.

[GregM]

I could not find those fonts in my 18.04 so I downloaded them and installed them (TTF files) for system use.
They show up now.
There was only one line that had "fonts" in it and that was the line I unchecked as in the photo
It seems better now but it's not 100%

[GregM]

While trying to look at the display a little closer I changed the screen scaling from 100% to 110%. This seems to have fixed the issue to a great extent.
Is there an add on or program that would allow scaling by less that 10% jumps? Maybe 5% jumps?

[claydoh]

I don't think so, but it might work from the command line using xrandr, but I do not remember if Plasma desktop itself can scale on a factor of less than 10% - it used to be only 1.0, 1.5, 2.0, etc iirc .

Have you logged out after the scaling? Some elements seem to need this to see the change.

Another thing to try, either in addition to, or instead of scaling, is to edit your font dpi and the antialiasing settings frtom within System Settings. For some reason Linux/Xorg defaults to 96 dpi, which is very often crap on higher resolution and/or larger screens. You might try enabling anti aliasing, and/or maybe adjusting the DPI up to the next step.

Also, if you do try some of these settings, this might be a time to try using the hdmi/dvi, which is a better video signal then analog.