hi, thanks for reporting this. we are currently looking into this issue in https://bugzilla.mozilla.org/show_bug.cgi?id=1435472

so far it appears to be an issue that only affects users who have turned off cleartype font rendering within their windows settings. so a workaround for the moment would either be to turn cleartype back on or disabling hardware acceleration in firefox: Firefox's performance settings

Hi philipp,

   Many thanks for your response.  May I ask what cleartype font rendering within their windows settings means, I haven't come across this before?

I have done as you said, but still having problems. At the moment, I have set the process content limit to its default, which is 4.

Many thanks

philipp said

hi, thanks for reporting this. we are currently looking into this issue in https://bugzilla.mozilla.org/show_bug.cgi?id=1435472 so far it appears to be an issue that only affects users who have turned off cleartype font rendering within their windows settings. so a workaround for the moment would either be to turn cleartype back on or disabling hardware acceleration in firefox: Firefox's performance settings

here's some more info about how to enable cleartype: https://www.howtogeek.com/howto/28790/tweak-cleartype-in-windows-7/

Hi Rosealinea1, sorry if philipp's reply wasn't 100% clear!

In the performance settings, there should be a checkbox labeled Use hardware acceleration when available and that is the feature you want to turn off. It should take effect the next time you exit out of Firefox and start it up again.

Rosealinea1 said

May I ask what cleartype font rendering within their windows settings means, I haven't come across this before?

ClearType is a technology in Windows used for font smoothing. It filled in the jagged edges caused by LCD screens with partial pixels. Some users think it makes everything look blurry and turn it off. A recent Firefox change apparently wasn't tested by enough users with ClearType turned off, or those who noticed it didn't report it.