The rendering engine often fails to draw pages correctly.
Text pages are often littered with black bars that obscure the lettering, almost like redaction. Refreshing the page usually solves the issue. Also, the bookmarks bar will often present with a pattern of dark gray and light gray blocks, which resolves when the mouse cursor passes over them. The attached images show what I mean.
ყველა პასუხი (2)
Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox.
A small dialog should appear. Click Start In Safe Mode (not Refresh).
Is the problem still there?
Thanks, FredMcD. I have not observed the effect since starting in safe mode. I guess, from the disappearance of my add-ons, that this means an add-on is the likely culprit, and that the next step is to introduce them one by one until the issue recurs. I'll try that and see what happens. It might take a day or three to report the results.