Firefox 33 and 34 - Some sites no longer correctly displayed (no style?)

Question

Hi,
I'm using firefox on a iMac. After upgrading to firefox 33 (and 34) some sites are no longer showing correctly. Seems to se like a problem about style&stylesheet, because I see them as a simple list of items and with default formatting (like blue/purple color for links).
I started trying the basics, emptying my cache and then directly removing and reinstalling firefox, but nothing changed. (If I reinstall version 32 it does work).
Then, I tried doing what I found on the forum, like disabling hardware acceleration, zooming and dezooming, nostyle vs basestyle, but nothing.
I could even simply go back to firefox 32, but a couple of those sites are sites I directly own, so I need them to work in any case.
Can you help me? Thank you!

Answer 1

Many site issues can be caused by corrupt cookies or cache.
* Clear the Cache and
* Remove Cookies '''''Warning ! ! '' This will log you out of sites you're logged in to.'''
Type '''about:preferences'''<Enter> in the address bar.
* '''Cookies;''' Select '''Privacy.''' Under '''History,''' select Firefox will '''Use Custom Settings.''' Press the button on the right side called '''Show Cookies.''' Use the search bar to look for the site. Note; There may be more than one entry. Remove '''All''' of them.
* '''Cache;''' Select '''Advanced > Network.''' Across from '''Cached Web Content,''' Press '''Clear Now.'''