I have been a Firefox user for a long time with the various Mac OSX releases. Since upgrading to Firefox 16 on OS 10.8.2 I have had serious rendering issues on all sorts of websites, but particularly those with complex imagery, streaming, or buttons & menus. It happens on all sorts of sites, but the worst sites are Amazon, eBay, & YouTube. The page render errors happen every day at some point during my browsing and require me to restart the browser to correct. After a restart, the pages will render correctly for random amounts of time, and then will render incorrectly suddenly. See the attached screenshots for examples.
I have tried removing add-ons, a clean reinstall of Firefox, a clean reinstall of the entire OS and all user apps & files (when upgrading my laptop), reinstalling the latest version of Java, and changing user agents. The problem happens on my iMac with 10.8.2 as well as my MacBook Pro and my former MacBook with 10.7.4, but not on my wife's MacBook Pro. It started when I upgraded to 10.7.4 and Firefox 16 and has persisted since then. It seems to have gotten worse as well, but i haven't measured that.
Anyone have any ideas as to what could be causing this?
It looks like you are missing CSS files.
Make sure that you do not have security software that is blocking files.
You can also try to disable IPv6 in Firefox as a test.
Try to reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files if this happens.
Thanks, how do I get the CSS files back where they should be and what software could be blocking it?
I do run the Ghostery, Adblock, and Better privacy extensions, but have been for years without problems, and when I disable them, I still get these page load errors.
You will have to reload pages that are corrupted and do not display properly.
Note that extension like Adblock Plus and Ghostery can block content and you always need to check that is it isn't working properly, but that would be consistent and can't be cured by reloading unless you unblock such content.
Thanks for the suggestions. I tried them all and they did seem to reduce the incidences of the loading/rendering errors a wee bit, but I still have the problem and it still occurs daily.
From the beginning, restarting Firefox and then going back to whichever website didn't display properly has fixed the problem temporarily. Is it possible that Firefox is intermittently writing a corrupt cache or temp file of some sort which is then cleared on a restart? What might be causing that?
Any ideas for a solution would be still be greatly appreciated as neither Safari nor Chrome allow for the same level of privacy control as Firefox.
You can check the Net log in the Web Console (Web Developer > Web Console;Ctrl+Shift+K) console to see if there are errors with retrieving files.
You need reload the web pages and bypass the cache to refresh possibly outdated or corrupted files from the server.
As you can see below, there are plenty of CSS warnings with regard to file retrieval. And given the error descriptions it makes sense that pages look the way they do. I took the screenshot right after the browser failed to load a couple of pages correctly.
The question remains as to why this is happening. Bypassing the cache to reload pages does seem to work (as does restarting the browser), but both of those options are not really solutions to the problem.
Then you can see if all files are retrieved successfully (GET: response: 200 OK).
You can try to disable IPv6.
You can try to reset (power off/on) the router.
Firefox 18 appears to have resolved the problem. Since its been out I haven't had any of the persistent rendering errors. Very occasionally a webpage will render with the errors for a fraction of a second, but then quickly corrects to the proper display.
Edit: And a couple of days later the same old problem reared its ugly head again upon going to the Amtrak site, which was really a mess.
Anyone have any idea how to stop this?