Tap here to go to the mobile version of the site.
Your Firefox is out of date and may contain a security risk! Upgrade Firefox

Support Forum

youtube wont play on firefox after flash is installed


brand new install of windows 7 pro 64 bit only other software installed is avast anti virus lavasoft adaware and malwarebytes, adobe reader that is it... no ms office, no games, nothing...

using firefox 23 ie 10 and basic google... not chrome

installed flash player - most recent version 11.8 something or other for 'other browsers' and pc will not play youtube videos. changed the hardware acceleration, deleted flash folder with cache... followed all the instructions and nothing...

ie would not play youtube either.

used adobe unistaller to unistall and reinstall repeatedly, nothing working.... youtube video will load and play about 2 seconds then get that black screen that says error and sends you to a google/youtube help screen where it tells you to install latest version of flash, check java, etc

finally found flash 10.3 and installed it. can watch youtube on ie, but still not on firefox.

don't want to be stuck on flash 10.3

this is pc for 79 year old woman... she uses it to watch videos and play lots of facebook games...

need firefox and flash to allow her to watch youtube and be able to play facebook flash games...

spent 7 hours now following every help article i can find.... install of os is fresh drivers were all updated a few days ago when os was installed...

she is not capable of fiddling with workarounds...


Additional System Details

Installed Plug-ins

  • Shockwave Flash 10.3 r183
  • Adobe PDF Plug-In For Firefox and Netscape 11.0.03


  • Firefox 23.0
  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:23.0) Gecko/20100101 Firefox/23.0
  • Support URL: http://support.mozilla.org/1/firefox/23.0/WINNT/en-US/


  • Troubleshooter 1.1a (troubleshooter@mozilla.org)
  • avast! Online Security 8.0.1489 (wrc@avast.com) (Inactive)


  • incrementalGCEnabled: True


  • adapterDescription: NVIDIA GeForce 6150SE nForce 430
  • adapterDescription2:
  • adapterDeviceID: 0x03d0
  • adapterDeviceID2:
  • adapterDrivers: nvd3dumx,nvd3dum
  • adapterDrivers2:
  • adapterRAM: 64
  • adapterRAM2:
  • adapterVendorID: 0x10de
  • adapterVendorID2:
  • direct2DEnabled: False
  • direct2DEnabledMessage: [u'']
  • directWriteEnabled: False
  • directWriteVersion: 6.2.9200.16571
  • driverDate: 1-31-2013
  • driverDate2:
  • driverVersion:
  • driverVersion2:
  • info: {u'AzureCanvasBackend': u'skia', u'AzureFallbackCanvasBackend': u'cairo', u'AzureContentBackend': u'none'}
  • isGPU2Active: False
  • numAcceleratedWindows: 0
  • numAcceleratedWindowsMessage: [u'blockedGfxCard']
  • numTotalWindows: 3
  • webglRenderer: Google Inc. -- ANGLE (NVIDIA GeForce 6150SE nForce 430)
  • windowLayerManagerType: Basic

Modified Preferences

  • browser.cache.disk.capacity: 358400
  • browser.cache.disk.smart_size.first_run: False
  • browser.cache.disk.smart_size.use_old_max: False
  • browser.cache.disk.smart_size_cached_value: 358400
  • browser.link.open_newwindow: 2
  • browser.places.smartBookmarksVersion: 4
  • browser.search.useDBForOrder: True
  • browser.sessionstore.restore_on_demand: False
  • browser.startup.homepage: http://www.google.com
  • browser.startup.homepage_override.buildID: 20130730113002
  • browser.startup.homepage_override.mstone: 23.0
  • browser.tabs.warnOnClose: False
  • browser.tabs.warnOnOpen: False
  • dom.mozApps.used: True
  • extensions.lastAppVersion: 23.0
  • gfx.direct2d.disabled: True
  • keyword.URL: http://securedsearch2.lavasoft.com/results.php?pr=vmn&id=adawaretb&v=3_2&hsimp=yhs-lavasoft&ent=bs&q=
  • layers.acceleration.disabled: True
  • network.cookie.prefsMigrated: True
  • places.database.lastMaintenance: 1376351709
  • places.history.expiration.transient_current_max_pages: 78814
  • plugin.disable_full_page_plugin_for_types: application/pdf
  • plugin.importedState: True
  • plugin.state.npdeployjava: 0
  • privacy.sanitize.migrateFx3Prefs: True
  • storage.vacuum.last.index: 0
  • storage.vacuum.last.places.sqlite: 1376351709


  • User JS: No
  • Accessibility: No
  • Top 10 Contributor
2388 solutions 21097 answers

Helpful Reply

Does Flash 10.3 work on Adobe's test page here:


I agree that you should install Flash 11.8 again. Then check whether Firefox is detecting it and listing it as Enabled on the add-ons page and check the above test page.

Or, in other words, is this problem limited to YouTube?

  • Top 10 Contributor
2388 solutions 21097 answers

This is some standard guidance that addresses the most common issues with Flash in Firefox. I'm sure you've seen some of it before, but just in case:

(1) Make sure all recorders/downloaders that interact with Flash media are as up-to-date as possible, or disable them.

(2) Disable hardware graphics acceleration in Firefox and in Flash

(A) {You mentioned already doing this} In Firefox, un-check the box here and restart:

orange Firefox button (or Tools menu) > Options > Advanced > General > "Use hardware acceleration when available"

(B) In Flash, see this support article from Adobe: http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues

(3) Disable protected mode (Windows Vista/7/8)

See this support article from Adobe under the heading "Last Resort": Adobe Forums: How do I troubleshoot Flash Player's protected mode for Firefox?

  • Top 10 Contributor
  • Moderator
10784 solutions 97065 answers

Boot the computer in Windows Safe Mode with network support (press F8 on the boot screen) as a test to see if that helps.