Did this just start in Firefox 42? One of the headline changes in Firefox 42 is adding a tracking blocker in private browsing windows. That kind of filtering may look like ad blocking.

If you are using private windows, you can turn off the anti-tracking feature on the Options page as a test. This article has more information on where to find that setting: What happened to Tracking Protection?.

If the problem occurs in regular windows, hmm, could you test in Firefox's Safe Mode? In Safe Mode, Firefox deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Not using private browsing.

I tried in safe mode the page does load fine. So I've been through slowly disabling extensions each time to work out which one it might be but the webpage still says I am using an ad blocker with them all disabled.

It doesn't display I have an ad blocker in safe mode or on other browsers..

If it was just one of the extensions I'd just remove it and carry on but it's not.

Thanks for your help!

hello, could you go to the firefox menu ≡ > help ? > troubleshooting information, copy the contents of that page and paste them here into a reply on the forum? this might give us a clue what is going on...

Yes, sure. Thanks!

Application Basics

Name: Firefox Version: 42.0 Build ID: 20151029151421 Update Channel: release User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:42.0) Gecko/20100101 Firefox/42.0 Multiprocess Windows: 0/1 (default: false) Safe Mode: false

Crash Reports for the Last 3 Days

All Crash Reports (including 5 pending crashes in the given time range)

Extensions

Name: DownThemAll! Version: 2.0.18.1-signed Enabled: true ID: {DDC359D1-844A-42a7-9AA1-88A850A938A8}

Name: Flash and Video Download Version: 1.77 Enabled: true ID: {bee6eb20-01e0-ebd1-da83-080329fb9a3a}

Name: Multifox Version: 3.2.1 Enabled: true ID: multifox@hultmann

Name: UnloadTab Version: 0.24.7.1-signed Enabled: true ID: unloadtab@firefox.ext

Name: WOT Version: 20151113 Enabled: true ID: {a0d7ccb3-214d-498b-b4aa-0e8fda9a7bf7}

Name: Bitdefender Wallet Version: 2.0 Enabled: false ID: bdwteffv19@bitdefender.com

Name: Go-Mobile Version: 2.2.6.1-signed Enabled: false ID: jid0-W5zY771zDsu5o7dTJ8KHm38w1xs@jetpack

Name: Grammarly Version: 2.32.1-signed Enabled: false ID: grammar.plugin@grammarly.com

Graphics

Adapter Description: Intel(R) HD Graphics Family Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igd12umd64 igdumdim32 igd10iumd32 igd10iumd32 igd12umd32 Adapter RAM: Unknown Asynchronous Pan/Zoom: none Device ID: 0x0a16 Direct2D Enabled: true DirectWrite Enabled: true (10.0.10240.16430) Driver Date: 8-4-2015 Driver Version: 10.18.15.4248 GPU #2 Active: false GPU Accelerated Windows: 1/1 Direct3D 11 (OMTC) Subsys ID: 08661025 Supports Hardware H264 Decoding: true Vendor ID: 0x8086 WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics Family Direct3D11 vs_5_0 ps_5_0) windowLayerManagerRemote: true AzureCanvasBackend: direct2d 1.1 AzureContentBackend: direct2d 1.1 AzureFallbackCanvasBackend: cairo 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.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.frecency_experiment: 4 browser.download.importedFromSqlite: true browser.places.smartBookmarksVersion: 7 browser.sessionstore.upgradeBackup.latestBuildID: 20151029151421 browser.startup.homepage_override.buildID: 20151029151421 browser.startup.homepage_override.mstone: 42.0 browser.tabs.warnOnClose: false dom.apps.reset-permissions: true dom.mozApps.used: true extensions.lastAppVersion: 42.0 font.internaluseonly.changed: true gfx.direct3d.last_used_feature_level_idx: 0 gfx.driver-init.appVersion: 42.0 gfx.driver-init.deviceID: 0x0a16 gfx.driver-init.driverVersion: 10.18.15.4248 gfx.driver-init.feature-d2d: true gfx.driver-init.feature-d3d11: true gfx.driver-init.status: 2 media.gmp-eme-adobe.abi: x86-msvc media.gmp-eme-adobe.lastUpdate: 1447060944 media.gmp-eme-adobe.version: 15 media.gmp-gmpopenh264.lastUpdate: 1432115421 media.gmp-gmpopenh264.version: 1.4 media.gmp-manager.buildID: 20151029151421 media.gmp-manager.lastCheck: 1447329228 media.hardware-video-decoding.failed: false media.webrtc.debug.aec_log_dir: C:\Users\Matthew\AppData\Local\Temp/ media.webrtc.debug.log_file: C:\Users\Matthew\AppData\Local\Temp/WebRTC.log network.auth.allow-subresource-auth: 2 network.cookie.prefsMigrated: true network.predictor.cleaned-up: true places.database.lastMaintenance: 1446872950 places.history.expiration.transient_current_max_pages: 104858 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true print.printer_Brother_MFC-J650DW_Printer.print_bgcolor: false print.printer_Brother_MFC-J650DW_Printer.print_bgimages: false print.printer_Brother_MFC-J650DW_Printer.print_colorspace: print.printer_Brother_MFC-J650DW_Printer.print_command: print.printer_Brother_MFC-J650DW_Printer.print_downloadfonts: false print.printer_Brother_MFC-J650DW_Printer.print_duplex: 1515870810 print.printer_Brother_MFC-J650DW_Printer.print_edge_bottom: 0 print.printer_Brother_MFC-J650DW_Printer.print_edge_left: 0 print.printer_Brother_MFC-J650DW_Printer.print_edge_right: 0 print.printer_Brother_MFC-J650DW_Printer.print_edge_top: 0 print.printer_Brother_MFC-J650DW_Printer.print_evenpages: true print.printer_Brother_MFC-J650DW_Printer.print_footercenter: print.printer_Brother_MFC-J650DW_Printer.print_footerleft: &PT print.printer_Brother_MFC-J650DW_Printer.print_footerright: &D print.printer_Brother_MFC-J650DW_Printer.print_headercenter: print.printer_Brother_MFC-J650DW_Printer.print_headerleft: &T print.printer_Brother_MFC-J650DW_Printer.print_headerright: &U print.printer_Brother_MFC-J650DW_Printer.print_in_color: true print.printer_Brother_MFC-J650DW_Printer.print_margin_bottom: 0.5 print.printer_Brother_MFC-J650DW_Printer.print_margin_left: 0.5 print.printer_Brother_MFC-J650DW_Printer.print_margin_right: 0.5 print.printer_Brother_MFC-J650DW_Printer.print_margin_top: 0.5 print.printer_Brother_MFC-J650DW_Printer.print_oddpages: true print.printer_Brother_MFC-J650DW_Printer.print_orientation: 0 print.printer_Brother_MFC-J650DW_Printer.print_page_delay: 50 print.printer_Brother_MFC-J650DW_Printer.print_paper_data: 9 print.printer_Brother_MFC-J650DW_Printer.print_paper_height: 11.00 print.printer_Brother_MFC-J650DW_Printer.print_paper_name: print.printer_Brother_MFC-J650DW_Printer.print_paper_size_type: 0 print.printer_Brother_MFC-J650DW_Printer.print_paper_size_unit: 1 print.printer_Brother_MFC-J650DW_Printer.print_paper_width: 8.50 print.printer_Brother_MFC-J650DW_Printer.print_plex_name: print.printer_Brother_MFC-J650DW_Printer.print_resolution: 1515870810 print.printer_Brother_MFC-J650DW_Printer.print_resolution_name: print.printer_Brother_MFC-J650DW_Printer.print_reversed: false print.printer_Brother_MFC-J650DW_Printer.print_scaling: 1.00 print.printer_Brother_MFC-J650DW_Printer.print_shrink_to_fit: true print.printer_Brother_MFC-J650DW_Printer.print_to_file: false print.printer_Brother_MFC-J650DW_Printer.print_unwriteable_margin_bottom: 0 print.printer_Brother_MFC-J650DW_Printer.print_unwriteable_margin_left: 0 print.printer_Brother_MFC-J650DW_Printer.print_unwriteable_margin_right: 0 print.printer_Brother_MFC-J650DW_Printer.print_unwriteable_margin_top: 0 print.printer_Brother_PS_Class_Driver_(Copy_1).print_bgcolor: false print.printer_Brother_PS_Class_Driver_(Copy_1).print_bgimages: false print.printer_Brother_PS_Class_Driver_(Copy_1).print_colorspace: print.printer_Brother_PS_Class_Driver_(Copy_1).print_command: print.printer_Brother_PS_Class_Driver_(Copy_1).print_downloadfonts: false print.printer_Brother_PS_Class_Driver_(Copy_1).print_duplex: 1515870810

If it works in Safe Mode and in normal mode with all extensions (Firefox menu button/Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via *"3-bar" menu button > Exit (Power button)

• Windows: File > Exit
• Mac: Firefox > Quit Firefox
• Linux: File > Quit

Did you check for any special icons at the left end of the location/address bar?

You can check the Net log in the Web Console and the Network Monitor (Firefox/Tools > Web Developer) to see if content fails to load or is possibly blocked.

• https://developer.mozilla.org/Tools/Web_Console
• https://developer.mozilla.org/Tools/Network_Monitor

Use Ctrl+F5 or Ctrl+Shift+R to reload the page and bypass the cache to generate a fresh log.