OS X 10.8.5, Firefox 24.5.0 1. Click on dropdown in Firefox's search field. 2. A list of installed search engine plugins appears along with "Manage Search engines...". Click this. 3. Click on "Get more search engines" 4. https://addons.mozilla.org/en-US/firefox/search/?atype=4 opens in a new tab. Select DuckDuckGo HTTPS/SSL or YouTube. 5. Click the green "+ Add to Firefox" button. 6. Firefox/mozilla.org complains in a dialog box: "Sorry, you need a Mozilla-based browser (such as Firefox) to install a search plugin." Oops, I'm using Firefox 24.5.0. Any ideas how to fix this? Thanks. Info from Help>Troubleshooting is below. ============================== Application Basics ------------------ Name: Firefox Version: 24.5.0 User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.8; rv:24.0) Gecko/20100101 Firefox/24.0 Extensions ---------- Name: Adblock Plus Version: 2.0.3 Enabled: true ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d} Name: BetterPrivacy Version: 1.68 Enabled: true ID: {d40f5e7b-d2cf-4856-b441-cc613eeffbe3} Name: Clip to DEVONthink Version: 1.2.3 Enabled: true ID: Clip-to-DEVONthink@devon-technologies.com Name: Collusion Version: 0.16.3 Enabled: true ID: jid1-F9UJ2thwoAm5gQ@jetpack Name: DoNotTrackPlus Version: 2.0.9 Enabled: true ID: donottrackplus@abine.com Name: DownloadHelper Version: 4.9.15 Enabled: true ID: {b9db16a4-6edc-47ec-a1f4-b86292ed211d} Name: DownThemAll! Version: 2.0.13 Enabled: true ID: {DDC359D1-844A-42a7-9AA1-88A850A938A8} Name: Element Hiding Helper for Adblock Plus Version: 1.2.1 Enabled: true ID: elemhidehelper@adblockplus.org Name: Flashblock Version: 1.5.17 Enabled: true ID: {3d7eb24f-2740-49df-8937-200b1cc08f8a} Name: Google/Yandex search link fix Version: 1.4.1 Enabled: true ID: jid0-XWJxt5VvCXkKzQK99PhZqAn7Xbg@jetpack Name: Lucifox Version: 0.8.4 Enabled: true ID: Lucifox@lucidor.org Name: Remove Cookies for Site Version: 0.62 Enabled: true ID: {06997db0-c027-4d5f-bd37-b0d9230226ea} Name: ScrapBook Version: 1.5.3 Enabled: true ID: {53A03D43-5363-4669-8190-99061B2DEBA5} Name: User Agent Switcher Version: 0.7.3 Enabled: true ID: {e968fc70-8f95-4ab9-9e79-304de2a71ee1} Name: Disconnect Version: 1.0.1 Enabled: false ID: disconnect@disconnect.me Name: selectivecookiedelete Version: 4.1 Enabled: false ID: selectivecookiedelete@siju.mathew Important Modified Preferences ------------------------------ accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 307200 browser.cache.disk.smart_size_cached_value: 768000 browser.cache.disk.smart_size.enabled: false browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.display.use_document_fonts: 0 browser.history_expire_days.mirror: 180 browser.places.smartBookmarksVersion: 4 browser.sessionstore.restore_on_demand: false browser.startup.homepage: file:///Volumes/Data/Oro/_Blank Page.html browser.startup.homepage_override.buildID: 20140421162246 browser.startup.homepage_override.mstone: 24.5.0 dom.mozApps.used: true extensions.lastAppVersion: 24.5.0 font.minimum-size.x-western: 13 font.name.monospace.x-western: Monaco font.name.sans-serif.x-western: Lucida Sans font.name.serif.x-western: Calibri font.size.variable.x-western: 13 gfx.blacklist.webgl.msaa: 4 network.cookie.prefsMigrated: true places.database.lastMaintenance: 1399518177 places.history.expiration.transient_current_max_pages: 104858 places.last_vacuum: 1331401559 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true plugin.state.iphotophotocast: 0 plugin.state.java: 0 plugin.state.sharepointbrowserplugin: 0 print.macosx.pagesetup-2: PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiPz4KPCFET0NUWVBFIHBsaXN0IFBVQkxJQyAiLS8vQXBwbGUvL0RURCBQTElTVCAxLjAvL0VO print.print_bgcolor: false print.print_bgimages: false print.print_colorspace: print.print_command: print.print_downloadfonts: false print.print_duplex: 0 print.print_evenpages: true print.print_footerleft: &U print.print_footerright: print.print_headerright: &D print.print_in_color: true print.print_margin_bottom: 0.5 print.print_margin_left: 0.5 print.print_margin_right: 0.5 print.print_margin_top: 0.5 print.print_oddpages: true print.print_orientation: 0 print.print_page_delay: 50 print.print_pagedelay: 500 print.print_paper_data: 0 print.print_paper_height: 11.00 print.print_paper_name: print.print_paper_size_type: 1 print.print_paper_size_unit: 0 print.print_paper_width: 8.50 print.print_plex_name: print.print_printer: print.print_resolution: 0 print.print_resolution_name: print.print_reversed: false print.print_scaling: 0.60 print.print_shrink_to_fit: false print.print_to_file: false print.print_unwriteable_margin_bottom: 17 print.print_unwriteable_margin_left: 25 print.print_unwriteable_margin_right: 25 print.print_unwriteable_margin_top: 17 privacy.clearOnShutdown.cookies: false privacy.clearOnShutdown.downloads: false privacy.clearOnShutdown.formdata: false privacy.clearOnShutdown.history: false privacy.clearOnShutdown.sessions: false privacy.cpd.cookies: false privacy.cpd.downloads: false privacy.cpd.formdata: false privacy.cpd.history: false privacy.cpd.sessions: false privacy.donottrackheader.enabled: true privacy.sanitize.migrateFx3Prefs: true privacy.sanitize.sanitizeOnShutdown: true privacy.sanitize.timeSpan: 0 security.OCSP.require: true security.warn_viewing_mixed: false storage.vacuum.last.index: 1 storage.vacuum.last.places.sqlite: 1399078504 Graphics -------- Device ID: 0x 166 GPU Accelerated Windows: 2/2 OpenGL Vendor ID: 0x8086 WebGL Renderer: Intel Inc. -- Intel HD Graphics 4000 OpenGL Engine windowLayerManagerRemote: false AzureCanvasBackend: quartz AzureContentBackend: none AzureFallbackCanvasBackend: none JavaScript ---------- Incremental GC: true Accessibility ------------- Activated: false Prevent Accessibility: 0 Library Versions ---------------- NSPR Expected minimum version: 4.10.2 Version in use: 4.10.2 NSS Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC NSSSMIME Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC NSSSSL Expected minimum version: 3.15.4 Basic ECC Version in use: 3.15.4 Basic ECC NSSUTIL Expected minimum version: 3.15.4 Version in use: 3.15.4