Firefox ver 31 latest doesn't play videos -

Question

Firefox will not play videos in or out of U-Tube. . All videos play in I.E. ver 11.0.10 without an issue
In Firefox I get a large black square that reduces to a black bar and then when I place the cursor in the area where the video should be I see a flashing rotating circle.
Just updated Firefox Ver 31RC1 today 7-16-14
Flash Plugin = Ver 14.0.0.145
Quicktime plugin = Ver Version: 7.7.5.0
Windows 7-64 All updates loaded
Application Basics
Name: Firefox
Version: 31.0
User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Firefox/31.0
Crash Reports for the Last 3 Days
Report ID: bp-4ae398ae-dc97-42ba-8287-e8f502140715
Submitted: 2 days ago
All Crash Reports
Extensions
Name: Adblock Plus
Version: 2.6.3
Enabled: true
ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}
Name: Address Bar Search
Version: 1.2
Enabled: true
ID: {badea1ae-72ed-4f6a-8c37-4db9a4ac7bc9}
Name: BetterPrivacy
Version: 1.68
Enabled: true
ID: {d40f5e7b-d2cf-4856-b441-cc613eeffbe3}
Name: DownloadHelper
Version: 4.9.22
Enabled: true
ID: {b9db16a4-6edc-47ec-a1f4-b86292ed211d}
Name: F.B. Purity - Cleans Up Facebook
Version: 9.9.1
Enabled: true
ID: [email protected]
Name: Garmin Communicator
Version: 4.1.0
Enabled: true
ID: {195A3098-0BD5-4e90-AE22-BA1C540AFD1E}
Name: Logitech Device Detection
Version: 1.23.0.5
Enabled: true
ID: [email protected]
Name: MAFIAAFire Redirector
Version: 0.9d
Enabled: true
ID: [email protected]
Name: MapsGalaxy
Version: 6.58.4.18298
Enabled: true
ID: 39ffxtbr@MapsGalaxy_39.com
Name: Skype Click to Call
Version: 7.2.15747.10003
Enabled: true
ID: {82AF8DCA-6DE9-405D-BD5E-43525BDAD38A}
Name: Adobe DLM (powered by getPlus(R))
Version: 1.6.2.63
Enabled: false
ID: {E2883E8F-472F-4fb0-9522-AC9BF37916A7}
Name: Advanced SystemCare Surfing Protection
Version: 1.0
Enabled: false
ID: [email protected]
Name: Hyperwords
Version: 6.5.3
Enabled: false
ID: {9A752782-D706-479b-98F8-3F66BF921692}
Graphics
Adapter Description: NVIDIA GeForce GTS 250
Adapter Drivers: nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um
Adapter RAM: 1024
ClearType Parameters: Gamma: 2200 Pixel Structure: R ClearType Level: 0 Enhanced Contrast: 50
Device ID: 0x0615
Direct2D Enabled: true
DirectWrite Enabled: true (6.2.9200.16571)
Driver Date: 3-4-2014
Driver Version: 9.18.13.3523
GPU #2 Active: false
GPU Accelerated Windows: 1/1 Direct3D 10
Vendor ID: 0x10de
WebGL Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTS 250 Direct3D9Ex vs_3_0 ps_3_0)
windowLayerManagerRemote: false
AzureCanvasBackend: direct2d
AzureContentBackend: direct2d
AzureFallbackCanvasBackend: cairo
AzureSkiaAccelerated: 0
Important Modified Preferences
accessibility.typeaheadfind: true
accessibility.typeaheadfind.flashBar: 0
browser.cache.disk.capacity: 358400
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: 4
browser.cache.memory.capacity: 65536
browser.display.show_image_placeholders: true
browser.display.use_document_fonts: 0
browser.history_expire_days.mirror: 180
browser.places.importBookmarksHTML: false
browser.places.smartBookmarksVersion: 7
browser.search.param.yahoo-fr: chr-greentree_ff&type=380920&ilc=12
browser.search.useDBForOrder: true
browser.sessionstore.upgradeBackup.latestBuildID: 20140714151536
browser.startup.homepage: http://www.msn.com/
browser.startup.homepage_override.buildID: 20140714151536
browser.startup.homepage_override.mstone: 31.0
browser.tabs.warnOnClose: false
browser.urlbar.autocomplete.enabled: true
dom.max_script_run_time: 1800
dom.mozApps.used: true
dom.w3c_touch_events.expose: false
extensions.lastAppVersion: 31.0
font.internaluseonly.changed: false
font.minimum-size.x-western: 14
font.size.fixed.x-western: 14
font.size.variable.x-western: 14
gfx.direct3d.checkDX10: false
gfx.direct3d.last_used_feature_level_idx: 1
network.cookie.prefsMigrated: true
network.http.max-connections: 48
network.http.max-connections-per-server: 16
network.http.max-persistent-connections-per-proxy: 16
network.http.max-persistent-connections-per-server: 8
network.http.pipelining.maxrequests: 8
network.http.request.max-start-delay: 0
places.database.lastMaintenance: 1405542420
places.history.expiration.transient_current_max_pages: 104858
places.history.expiration.transient_optimal_database_size: 167772160
places.last_vacuum: 1296747843
plugin.disable_full_page_plugin_for_types: application/pdf,application/vnd.adobe.xfdf,application/vnd.fdf
plugin.expose_full_path: true
plugin.importedState: true
plugin.state.flash: 1
plugin.state.nppl: 0
plugin.state.npqtplugin: 1
print.print_printer: Adobe PDF
print.printer_Epson_Stylus_Photo_R200_(M).print_bgcolor: false
privacy.donottrackheader.enabled: true
privacy.sanitize.migrateFx3Prefs: true
security.warn_viewing_mixed: false
storage.vacuum.last.index: 1
storage.vacuum.last.places.sqlite: 1404830167
user.js Preferences
Your profile folder contains a user.js file, which includes preferences that were not created by Firefox.
JavaScript
Incremental GC: true
Accessibility
Activated: false
Prevent Accessibility: 0
Library Versions
NSPR
Expected minimum version: 4.10.6
Version in use: 4.10.6
NSS
Expected minimum version: 3.16.2 Basic ECC
Version in use: 3.16.2 Basic ECC
NSSSMIME
Expected minimum version: 3.16.2 Basic ECC
Version in use: 3.16.2 Basic ECC
NSSSSL
Expected minimum version: 3.16.2 Basic ECC
Version in use: 3.16.2 Basic ECC
NSSUTIL
Expected minimum version: 3.16.2
Version in use: 3.16.2
Experimental Features
---------------------

Answer 1

On the MSN site, could you open the Web Console (Ctrl+Shift+k) in the lower part of the tab and click Network, then try a video in the upper part of the tab? Click the Size column a couple times to bring the largest items to the top and watch for the player.swf file to load and then see whether any media files load. Sample screen shot attached.
Anything?