After a very big update, Firefox and Thunderbird do not work well anymore. Thunderbird has been resolved after a later update.
But Firefox does not work well, no clear screen. Is not to be used like that.
Firefox version 53.0-6.16 x64.

For the time being, but using Opera.

OS: openSUSE Tumbleweed
KDE PLasma 5.9.5
Frameworks 5.33.0
QT 5.7.1
Kernel 4.11.2-1 default
Type OS 64-bit