Since some days many website buttons have disappeared in my FireFox browser, e.g. buttons below each contribution or within the reply edit window. Hovering over a button makes the hint text appear, i.e. the buttons still are there only invisible.
What has changed, where should I look for possible adjustments?
I cannot get a newer FF version on Mint and I have no ads installed. I'll try to clear the cache and cookies as soon as I know how to do that. For now I'll restart FF and look again.