Constant errors, hang, all sites, including this
Windows &, new install (work), new Dell Optiplex 390, new install of FF 20.0.1
Pretty much constant hangs. FF unresponsive for over a minute on most pageloads (news.google.com, Washington post, Yahoo, ABC news, etc) Error console fills up after hang ends with errors and warning on css properties, js errors, etc. Seems especially prevelent (but not limited to) new tabs.
Looking at about 3 dozen errors for this site. Examples include
Timestamp: 4/17/2013 1:59:41 PM
Warning: Expected declaration but found '*'. Skipped to next declaration. Source File: http://support.cdn.mozilla.net/media/css/common-min.css?build=0021b54 Line: 1
Google news in another tab (sitting, while working on this tab) just produced another "stopped script" warning.
A few dozen more error log entries, examples include
Timestamp: 4/17/2013 2:11:05 PM Warning: Unknown property '-moz-border-radius'. Declaration dropped. Source File: http://s.ytimg.com/yts/cssbin/www-embed-vfl0pSeeF.css Line: 1
Timestamp: 4/17/2013 2:15:34 PM Warning: Expected media feature name but found 'modernizr'. Source File: http://support.mozilla.org/en-US/questions/933149 Line: 1
Timestamp: 4/17/2013 2:15:34 PM Warning: Expected color but found 'top'. Error in parsing value for 'background-image'. Declaration dropped. Source File: http://support.cdn.mozilla.net/media/css/common-min.css?build=0021b54 Line: 1
Timestamp: 4/17/2013 2:11:05 PM Warning: Error in parsing value for 'background-image'. Declaration dropped. Source File: http://s.ytimg.com/yts/cssbin/www-embed-vfl0pSeeF.css Line: 1
Wšykne wótegrona (1)
Hi tommymiles, don't worry about style warnings; in order to cater to older browsers and special browser-specific features, websites commonly use many rules that Firefox considers invalid.
Most major websites are pulling in resources from numerous servers, potentially a dozen or more, and Firefox often seems to wait on the slowest one. Still, Google News should work fine, so there's something else going on here.
If you decide to do further troubleshooting, check out this article and see whether any of the issues are relevant to you: Firefox hangs or is not responding - How to fix.