Are you using the Firefox version from the Mozilla server? *https://www.mozilla.org/en-US/firefox/all/ You can create a new profile to test if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles *http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems. *http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Thanks. This solution is not completely, but make wide solution and for me is new practice. Unfortunately, connection to web over the Firefox Quantum 66.0.3 in the linux Fatdog64 is probleb. That must be resolvig any way. Chrome connection is OK, but he is irritating.