Can't open Firefox with Yahoo home page. Have done so for years. Needs to be fixed.

Question

Received error message: An error occurred during a connection to www.yahoo.com. security library: improperly formatted DER-encoded message. (Error code: sec_error_bad_der)
The page you are trying to view cannot be shown because the authenticity of the received data could not be verified.
Please contact the website owners to inform them of this problem.
Been using Yahoo as my home page for years and years and all of a sudden it's a problem. I can open it easily on Safari browser even though I don't have an Apple computer. So the problem has to be with Firefox, not Yahoo. I've read all of your solutions, tried troubleshooting them, and it still doesn't work. I contacted Yahoo and they haven't responded, probably because the problem isn't on their end, but on Firefox.
Please fix or I will have to stop using Firefox as my primary browser.

Answer 1

I copied all of this. BTW I need something very basic as I am not tech savvy at all. Thank you.
Application Basics
Name Firefox
Version 33.1
Update History
User Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:33.0) Gecko/20100101 Firefox/33.0
Profile Folder
Enabled Plugins about:plugins
Build Configuration about:buildconfig
Memory Use about:memory
Multiprocess Windows 0/4
Crash Reports for the Last 3 Days
Report ID Submitted
All Crash Reports (including 1 pending crash in the given time range)
Extensions
Name Version Enabled ID
Avast Online Security 10.0.2502.149 false [email protected]
McAfee Security Scan Plus 1.0 false {e4f94d1e-2f53-401e-8885-681602c0ddd8}
McAfee SiteAdvisor 3.7.1 false {4ED1F68A-5463-4931-9384-8FFF5ED91D92}
Graphics
Adapter Description Intel(R) Graphics Media Accelerator HD
Adapter Drivers igdumd64 igd10umd64 igdumdx32 igd10umd32
Adapter RAM Unknown
Device ID 0x0046
Direct2D Enabled Blocked for your graphics driver version. Try updating your graphics driver to version 8.1500.1000.2202 or newer.
DirectWrite Enabled false (6.2.9200.16571)
Driver Date 1-25-2010
Driver Version 8.15.10.2057
GPU #2 Active false
GPU Accelerated Windows 4/4 Direct3D 11 (OMTC)
Vendor ID 0x8086
WebGL Renderer Google Inc. -- ANGLE (Intel(R) Graphics Media Accelerator HD Direct3D9Ex vs_3_0 ps_3_0)
windowLayerManagerRemote true
AzureCanvasBackend skia
AzureContentBackend cairo
AzureFallbackCanvasBackend cairo
AzureSkiaAccelerated 0
Important Modified Preferences
Name Value accessibility.typeaheadfind.flashBar 0
browser.cache.disk.capacity 358400
browser.cache.disk.smart_size.first_run false
browser.cache.disk.smart_size.use_old_max false
browser.cache.frecency_experiment 3
browser.places.smartBookmarksVersion 7
browser.sessionstore.upgradeBackup.latestBuildID 20141106120505
browser.startup.homepage https://www.yahoo.com/#
browser.startup.homepage_override.buildID 20141106120505
browser.startup.homepage_override.mstone 33.1
dom.mozApps.used true
extensions.lastAppVersion 33.1
font.internaluseonly.changed false
font.minimum-size.x-western 13
media.gmp-gmpopenh264.lastUpdate 1414111943
media.gmp-gmpopenh264.version 1.1
media.gmp-manager.lastCheck 1417289586
network.cookie.prefsMigrated true
places.database.lastMaintenance 1417289587
places.history.expiration.transient_current_max_pages 73519
plugin.disable_full_page_plugin_for_types application/pdf
plugin.importedState true
print.printer_HP_Deskjet_F4500_series.print_bgcolor false
print.printer_HP_Deskjet_F4500_series.print_bgimages false
print.printer_HP_Deskjet_F4500_series.print_colorspace
print.printer_HP_Deskjet_F4500_series.print_command
print.printer_HP_Deskjet_F4500_series.print_downloadfonts false
print.printer_HP_Deskjet_F4500_series.print_duplex 1515870810
print.printer_HP_Deskjet_F4500_series.print_edge_bottom 0
print.printer_HP_Deskjet_F4500_series.print_edge_left 0
print.printer_HP_Deskjet_F4500_series.print_edge_right 0
print.printer_HP_Deskjet_F4500_series.print_edge_top 0
print.printer_HP_Deskjet_F4500_series.print_evenpages true
print.printer_HP_Deskjet_F4500_series.print_footercenter
print.printer_HP_Deskjet_F4500_series.print_footerleft &PT
print.printer_HP_Deskjet_F4500_series.print_footerright &D
print.printer_HP_Deskjet_F4500_series.print_headercenter
print.printer_HP_Deskjet_F4500_series.print_headerleft &T
print.printer_HP_Deskjet_F4500_series.print_headerright &U
print.printer_HP_Deskjet_F4500_series.print_in_color true
print.printer_HP_Deskjet_F4500_series.print_margin_bottom 0.5
print.printer_HP_Deskjet_F4500_series.print_margin_left 0.5
print.printer_HP_Deskjet_F4500_series.print_margin_right 0.5
print.printer_HP_Deskjet_F4500_series.print_margin_top 0.5
print.printer_HP_Deskjet_F4500_series.print_oddpages true
print.printer_HP_Deskjet_F4500_series.print_orientation 0
print.printer_HP_Deskjet_F4500_series.print_page_delay 50
print.printer_HP_Deskjet_F4500_series.print_paper_data 1
print.printer_HP_Deskjet_F4500_series.print_paper_height 11.00
print.printer_HP_Deskjet_F4500_series.print_paper_name
print.printer_HP_Deskjet_F4500_series.print_paper_size_type 0
print.printer_HP_Deskjet_F4500_series.print_paper_size_unit 0
print.printer_HP_Deskjet_F4500_series.print_paper_width 8.50
print.printer_HP_Deskjet_F4500_series.print_plex_name
print.printer_HP_Deskjet_F4500_series.print_resolution 1515870810
print.printer_HP_Deskjet_F4500_series.print_resolution_name
print.printer_HP_Deskjet_F4500_series.print_reversed false
print.printer_HP_Deskjet_F4500_series.print_scaling 1.00
print.printer_HP_Deskjet_F4500_series.print_shrink_to_fit true
print.printer_HP_Deskjet_F4500_series.print_to_file false
print.printer_HP_Deskjet_F4500_series.print_unwriteable_margin_bottom 0
print.printer_HP_Deskjet_F4500_series.print_unwriteable_margin_left 0
print.printer_HP_Deskjet_F4500_series.print_unwriteable_margin_right 0
print.printer_HP_Deskjet_F4500_series.print_unwriteable_margin_top 0
privacy.sanitize.migrateFx3Prefs true
privacy.sanitize.timeSpan 0
storage.vacuum.last.index 1
storage.vacuum.last.places.sqlite 1416776213
Important Locked Preferences
Name Value
JavaScript
Incremental GC true
Accessibility
Activated false
Prevent Accessibility 0
Library Versions
Expected minimum version Version in use
NSPR 4.10.7 4.10.7
NSS 3.17.2 Basic ECC 3.17.2 Basic ECC
NSSSMIME 3.17.2 Basic ECC 3.17.2 Basic ECC
NSSSSL 3.17.2 Basic ECC 3.17.2 Basic ECC
NSSUTIL 3.17.2 3.17.2
Experimental Features