Firefox suddenly stopped opening webpages, while other browser work properly. I checked Proxy settings and everything that is mentioned in the central help page, but still no solution found... In addition, i tried to re-install Firefox many times, without a result. In the time these lines are written, I am using Google Chrome to surf the web. Neither proxy settings, nor the true/false ipV6 values helped. The "symptoms" are as following: --> The programm itself starts correctly, at usual speed, with no crashes or error messages to pop-up. --> No page is displayed, neither the home page, nor any other one. I only see a blank white page. -->The name of the starting tab, as of any other new tab I try to open is "(Untitled)" -->There is no probability of errors in the Internet Line, because I am using it right now, running Chrome. -->The full scan results are totally clean, using Panda Internet Security 2011, activated and updated. -->The Error Console shows the following messages: Could not read chrome manifest file 'C:\Program Files\Mozilla Firefox\extensions\{972ce4c6-7e08-4474-a285-3208198ce6fd}\chrome.manifest'. Warning: XUL box for _moz_generated_content_after element contained an inline #text child, forcing all its children to be wrapped in a block. Source File: chrome://browser/content/browser.xul Line: 0 Warning: WARN addons.updates: HTTP Request failed for an unknown reason Source File: resource://gre/modules/AddonUpdateChecker.jsm Line: 503 Warning: WARN addons.repository: Search failed when repopulating cache Source File: resource://gre/modules/AddonRepository.jsm Line: 573 Error: Livemark Service: feed processor received an invalid channel for http://fxfeeds.mozilla.com/en-US/firefox/headlines.xml Source File: resource://gre/components/nsLivemarkService.js Line: 635 Error: Livemark Service: feed processor received an invalid channel for http://www.dent.uoa.gr/data/feeds/announcements_atom.rss Source File: resource://gre/components/nsLivemarkService.js Line: 635. These Error messages appear in the Error Console of the just now downloaded Firefox 4.0. In the previous version, 3.6.12, before removing it, I noticed two more error messages in the error console, like the two last as listed above: With the nema ERROR.