Characters go missing or are replaced by special characters

[Avathar]

Hi!

Since a few weeks im getting a rather weired problem and i was not able to find a solution:
Sometimes (usually if the laptop runs more than 24 hours), characters in several applications (firefox, chrome, pidgin, etc) get's replaced by special characters or disappear at all.
When this happens, sometimes restarting the application work, but most of the time i have to reboot. At first i thought it only affects gtk applications, but recently i also got the problems in plasma widgets (f.e. when i press alt+f2), dolphin, etc

Here's a screenshot of firefox:


I really can't figure out what's at fault here..any help is apreciated.

[millusions]

could it be overheating? since you say this happens after it's been on for a while
do you have any temp mon?

[Snowhog]

It's a mozilla cache issue. You can fix it by deleting the firefox cache contents and logging out/in and starting Firefox.

[Avathar]

@millusions
Well, i'm not 100% sure, but i don't think so..this problem stays also when i put the laptop into standby/hibernation..and usually the temperature doesn't go up that much

@Snowhog
I'm also getting this problem in google chrome, pidgin, plasma widgets,...so i think it can't be an issue only related to firefox

[millusions]

that's very strange indeed!

1. i'd try to change the default font
if 1 fails:
2. i would monitor temp - could be some video artifacting, its unlikely but what are the options?

[Avathar]

Well, fortunately i havn't had this issue in the last several days. But from what i've noticed changing the fonts when this problem occurs helps. Also sometimes changing the dpi settings, or the graphic effects, renderer etc does. But when i change it back to the original settings the problem persists.
I'll monitor the temperature more thoroughly, but suppose this is the reason, shouldn't that problem go away when the temperature reaches a normal level again?

Maybe i'll just start fresh with plasma 5 when it get's more stable and i have the time to do a fresh install..
Btw thanks for your help

[jlittle]

KDE uses a font cache, but I can't remember the details; I only mention it because no-one else has. Perhaps it is getting corrupted.

Regards, John Little