When you check the default search engine setting, is DuckDuckGo still an option? See: [[Change your default search settings in Firefox]] If not, then on Settings page > Search panel > Shortcuts box scroll down and look for "Restore Default Search Engines" to add it back to the list. If DDG ''is'' your default but searches are not working, what happens? For example: * there is an error message - what does it say? * blank results page * results come up on a different site