Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac=Options) key, and then starting Firefox. Is the problem still there?

While still in Safe Mode,

Type about:support in the address bar and press Enter. Under the main banner, press the button; Copy Text To Clipboard.. Then in the reply box at the bottom of this page, do a right click in the box and select Paste. This will show us your system details. No Personal Information Is Collected.

Application Basics

Name: Firefox Version: 42.0 Build ID: 20151029151421 Update Channel: release User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:42.0) Gecko/20100101 Firefox/42.0 Multiprocess Windows: 0/1 (default: false) Safe Mode: true

Crash Reports for the Last 3 Days

All Crash Reports

Extensions

Name: 1Password Version: 3.9.20 Enabled: false ID: onepassword@agilebits.com

Name: Adblock Plus Version: 2.6.13 Enabled: false ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}

Name: Add to Amazon Wish List Button Version: 1.10.1-signed Enabled: false ID: amznUWL2@amazon.com

Name: Adobe Acrobat - Create PDF Version: 1.2 Enabled: false ID: web2pdfextension@web2pdf.adobedotcom

Name: Amazon Shopping Assistant by Spigot Version: 1.7 Enabled: false ID: saamazon@mybrowserbar.com

Name: Ebay Shopping Assistant by Spigot Version: 1.7 Enabled: false ID: saebay@mybrowserbar.com

Name: Elf 1.15 Community Toolbar Version: 3.21.0.1 Enabled: false ID: {b9d63c58-90cc-428b-8d3b-cbb88eb07e7e}

Name: Ghostery Version: 5.4.9 Enabled: false ID: firefox@ghostery.com

Name: Searchme Version: 2.8 Enabled: false ID: searchme@mybrowserbar.com

Name: Slick Savings Version: 3.2 Enabled: false ID: savingsslider@mybrowserbar.com

Graphics

Asynchronous Pan/Zoom: none Device ID: 0x6821 GPU Accelerated Windows: 0/1 Basic Supports Hardware H264 Decoding: false Vendor ID: 0x1002 windowLayerManagerRemote: false AzureCanvasBackend: skia AzureContentBackend: quartz AzureFallbackCanvasBackend: none AzureSkiaAccelerated: 0

Important Modified Preferences

accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 358400 browser.cache.disk.filesystem_reported: 1 browser.cache.disk.hashstats_reported: 1 browser.cache.disk.smart_size_cached_value: 358400 browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.frecency_experiment: 2 browser.display.screen_resolution: 96 browser.display.use_document_fonts: 0 browser.download.folderList: 0 browser.download.importedFromSqlite: true browser.download.manager.alertOnEXEOpen: true browser.download.manager.closeWhenDone: true browser.history_expire_days.mirror: 40 browser.newtab.url: about:newtab browser.places.importBookmarksHTML: false browser.places.importDefaults: false browser.places.leftPaneFolderId: -1 browser.places.migratePostDataAnnotations: false browser.places.smartBookmarksVersion: 7 browser.places.updateRecentTagsUri: false browser.search.suggest.enabled: false browser.sessionstore.upgradeBackup.latestBuildID: 20151029151421 browser.startup.homepage: https://www.facebook.com/|https://twitter.com/?lang=en browser.startup.homepage_override.buildID: 20151029151421 browser.startup.homepage_override.mstone: 42.0 browser.tabs.loadInBackground: false browser.tabs.warnOnClose: false browser.zoom.full: false dom.apps.reset-permissions: true dom.mozApps.used: true dom.w3c_touch_events.expose: false extensions.lastAppVersion: 42.0 font.minimum-size.x-western: 12 font.size.fixed.x-western: 15 font.size.variable.x-western: 24 gfx.blacklist.direct2d: 3 gfx.blacklist.layers.direct3d9: 3 keyword.URL: https://search.yahoo.com/search?fr=spigot-adr-ffmac&ei=utf-8&ilc=12&type=216107&p= layers.acceleration.disabled: true media.gmp-gmpopenh264.abi: x86_64-gcc3-u-i386-x86_64 media.gmp-gmpopenh264.lastUpdate: 1447885177 media.gmp-gmpopenh264.version: 1.5.1 media.gmp-manager.buildID: 20151029151421 media.gmp-manager.lastCheck: 1449250821 media.webrtc.debug.aec_log_dir: /tmp/ media.webrtc.debug.log_file: /tmp/WebRTC.log network.auth.allow-subresource-auth: 2 network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1448669698 places.history.expiration.transient_current_max_pages: 104858 places.history.expiration.transient_optimal_database_size: 167772160 places.last_vacuum: 1316653208 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true plugin.state.adobepdfviewernpapi: 0 print.print_bgcolor: false print.print_bgimages: false print.print_colorspace: print.print_command: print.print_downloadfonts: true print.print_duplex: 0 print.print_evenpages: true 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: 673185794 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: 1.00 print.print_shrink_to_fit: true print.print_to_file: false print.print_unwriteable_margin_bottom: 17 print.print_unwriteable_margin_left: 17 print.print_unwriteable_margin_right: 17 print.print_unwriteable_margin_top: 17 privacy.cpd.downloads: false privacy.cpd.formdata: false privacy.cpd.history: false privacy.cpd.sessions: false privacy.sanitize.migrateFx3Prefs: true privacy.sanitize.promptOnSanitize: false privacy.sanitize.timeSpan: 0 security.OCSP.signingCA: Builtin Object Token:IPS CLASE1 root security.OCSP.URL: security.warn_entering_weak: false security.warn_viewing_mixed: false storage.vacuum.last.index: 1 storage.vacuum.last.places.sqlite: 1447375948

Important Locked Preferences

JavaScript

Incremental GC: true

Accessibility

Activated: false Prevent Accessibility: 0

Library Versions

NSPR Expected minimum version: 4.10.10 Version in use: 4.10.10

NSS Expected minimum version: 3.19.4 Basic ECC Version in use: 3.19.4 Basic ECC

NSSSMIME Expected minimum version: 3.19.4 Basic ECC Version in use: 3.19.4 Basic ECC

NSSSSL Expected minimum version: 3.19.4 Basic ECC Version in use: 3.19.4 Basic ECC

NSSUTIL Expected minimum version: 3.19.4 Version in use: 3.19.4

Experimental Features

Firefox opens in safe mode. I have put the pasted data in my previous response.

It could be the work of one of your add-ons. Type about:addons<enter> in the address bar to open your Add-ons Manager. Hot key; <Control>(Mac:<Command>)<Shift> A)

In the Add-ons Manager, on the left, select Extensions. Disable a few add-ons, then Restart Firefox.

Some added toolbar and anti-virus add-ons are known to cause Firefox issues. Disable All of them.

If the problem continues, disable some more (restarting FF). Continue until the problem is gone. After, you know what group is causing the issue. Re-enable the last group ONE AT A TIME (restarting FF) until the problem returns.

Once you think you found the problem, disable that and re-enable all the others, then restart again. Let us know who the suspect is detective.

No one will ever know. I turned them all off, then on, one by one, and the browser worked properly through the whole process, and continues to work now.

Something about doing all this apparently fixed it, whatever it was.

I never really wanted to know what it was; I just wanted it to stop, which it has. Thank you!

It could have been a corrupt file that was overwritten.

Glad to help. Safe Surfing.