Have you tried a new profile? Have you tried reinstalling Firefox? If it is not an extension causing the problem, it could be something else in the profile or something wrong with the application itself. This might give you some tips: http://kb.mozillazine.org/Creating_a_new_default_profile http://kb.mozillazine.org/Standard_diagnostic_-_Firefox

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

• http://www.bleepingcomputer.com/tutorials/how-to-start-windows-in-safe-mode/

Do a malware check with several malware scanning programs on the Windows computer. Please scan with all programs because each program detects different malware. All these programs have free versions.

Make sure that you update each program to get the latest version of their databases before doing a scan.

• Malwarebytes' Anti-Malware:
  http://www.malwarebytes.org/mbam.php
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender:
  http://windows.microsoft.com/en-us/windows/using-defender
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• Kasperky Free Security Scan:
  http://www.kaspersky.com/security-scan

You can also do a check for a rootkit infection with TDSSKiller.

• Anti-rootkit utility TDSSKiller:
  http://support.kaspersky.com/5350?el=88446

See also:

• "Spyware on Windows": http://kb.mozillazine.org/Popups_not_blocked
• https://support.mozilla.org/kb/troubleshoot-firefox-issues-caused-malware

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,

In the address bar, type about:crashes<enter>. Note: If any reports do not have BP in front of the numbers/letters, click it and select Submit.

Using your mouse, mark the most resent 7 - 10 crash reports, and copy them. Now go to the reply box below and paste them in.

If you can't get Firefox to open, you will have to do this the hard way. https://support.mozilla.org/en-US/kb/mozillacrashreporter Open the file browser / explorer on your computer. Note: You may have to enable Show Hidden Folders / Files. Enter this in the address bar;

Windows: %APPDATA%\Mozilla\Firefox\Crash Reports\submitted Win 7/Vista: C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Crash Reports\submitted Win XP/2000: C:\Documents and Settings\<username>\Application Data\Mozilla\Firefox\Crash Reports\submitted

Mac OS: /Users/<username>/Library/Application Support/Firefox/Crash Reports/submitted Linux: /home/<username>/.mozilla/firefox/Crash Reports/submitted

Copy the last 5-7 Recent File Names in the folder. Post the information in the reply box below.

Thanks to all who replied..The safe mode gives the same problems (server not found) when I know it's there on another tag...there's over 100 crash reports.....all in a short timespan 478f837a-4f6b-4dd5-85bd-3fa5612b9fbf 21/06/2015 17:30 ead6deed-7102-49fa-b1da-145c1697ce9a 21/06/2015 17:30 3b1bdf19-b406-46de-ac85-e59f876783de 21/06/2015 17:30 e91a6cc7-2e63-4fb4-91ac-2fb9a63dd174 21/06/2015 17:29 3b262de3-d6f0-4106-8bfb-5087ee8347fa 21/06/2015 17:29 1a4fda8f-34e9-41ea-9964-aa736dbd3c1f 21/06/2015 17:29 14e4141a-304f-4acd-9ab9-e24ee007fb23 21/06/2015 17:28 979cabb0-c56d-47e8-8221-14980ec6ce44 21/06/2015 17:28 d0cdbdb2-db06-4bef-ac52-4ac86f6aac61 21/06/2015 17:28 15ddc1a4-90e8-44a6-b20a-669fd5b97f18 21/06/2015 17:27 d8f93706-6e8f-41b4-8727-d6c5197607c9 21/06/2015 17:27 17999e35-e773-4e8a-a720-82c36d386b88 21/06/2015 17:27 31581c7c-a08c-427c-986f-094d07fab2fc 21/06/2015 17:27 f1adcf11-ab26-4976-aeaf-0651de94bf0c 21/06/2015 17:27 586897ff-545e-44fa-8cf5-de208bac3b80 21/06/2015 17:23 14a5fdbd-8c65-4529-9467-5d31439ca7df 21/06/2015 17:22 9514c374-d1e9-4bdd-a261-b728e44de6b5 21/06/2015 17:22 16738f8b-e19c-456c-b999-048dc6e0a0a0 21/06/2015 17:21 f671b88a-e731-49b7-a962-44edd644ff15 21/06/2015 17:21 d6072fcc-bb77-4c57-ad1a-9c1335eb6e1f 21/06/2015 17:21 3b95eb42-4dc8-4d9e-b93a-6692ec79aecb 21/06/2015 17:21

A malware issue; I'm having suspicions that since my ACER E5/871 works fine; I can only assume there is an architecture problem with the Lenovo B50....however that cannot be so ?

Windows defender found nothing out of the blue....I'm beginning to suspect the Lenovo B50 architecture/ build, but that can't be so, as there's millions out there and using FF ?..; my ACER doesn't exhibit the same issues. Way FF connects..Checked Ip4 ret/send ok; LAN to DSL wired; wireless diasbled, all obvious things done. I've even deleted the months-free Mcafee and resorted to only windows protection.. cleared out browser and cookie records.

Only crash reports that have a bp- prefix have been submitted.

If the "bp-" prefix is missing then click its line on the about:crashes page to submit the crash report and the crash report will get a "bp-" prefix (do not add it yourself).

tried that.... comes up...."400. That’s an error".

Unfortunately, the crashes and hangup's persist....Task manager created a dump file (dmp) of problem but cannot find it. I'm fast loosing usable hope in this mess other than abandon FF as a non reliable browser. No apols as I'm spending far too much time debugging without avail. ..and yet today the list of dp crashes continues.

FredMcD said

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, In the address bar, type about:crashes<enter>. Note: If any reports do not ...................................... Windows: %APPDATA%\Mozilla\Firefox\Crash Reports\submitted None of this works in Win8.1 -....................................................... have BP in front of the numbers/letters, click it and select Submit. Using your mouse, mark the most resent 7 - 10 crash reports, and copy them. Now go to the reply box below and paste them in.

---

If you can't get Firefox to open, you will have to do this the hard way. https://support.mozilla.org/en-US/kb/mozillacrashreporter Open the file browser / explorer on your computer. Note: You may have to enable Show Hidden Folders / Files. Enter this in the address bar;

Win 7/Vista: C:\Users\<username>\AppData\Roaming\Mozilla\Firefox\Crash Reports\submitted Win XP/2000: C:\Documents and Settings\<username>\Application Data\Mozilla\Firefox\Crash Reports\submitted

Mac OS: /Users/<username>/Library/Application Support/Firefox/Crash Reports/submitted Linux: /home/<username>/.mozilla/firefox/Crash Reports/submitted

Copy the last 5-7 Recent File Names in the folder. Post the information in the reply box below.

In any of your reinstalls, did you use this procedure?

Clean Reinstall

We use this name, but it's not about removing your settings, it's about making sure the program files are clean (no inconsistent, corrupted, or alien code files). As described below, this process does not disturb your existing settings. Do NOT uninstall Firefox, that's not needed.

(1) Download a fresh installer for Firefox 38.0.5 from https://www.mozilla.org/firefox/all/ to a convenient location. (Scroll down to your preferred language.)

(2) Exit out of Firefox (if applicable).

(3) Rename the program folder, either:

(64-bit Windows folder names)

C:\Program Files (x86)\Mozilla Firefox

to

C:\Program Files (x86)\OldFirefox

(32-bit Windows folder names)

C:\Program Files\Mozilla Firefox

to

C:\Program Files\OldFirefox

(4) Run the installer you downloaded in #1. It should automatically connect to your existing settings.

Will a cleanly reinstalled Firefox run for a while -- long enough to submit at least one crash report from the about:crashes page?

Note: Some plugins may exist only in that OldFirefox folder. If something essential is missing, look in these folders:

• \OldFirefox\Plugins
• \OldFirefox\browser\plugins

Did you post from the Firefox with the problem? In other words, Firefox is not completely blocked, but you get "server not found" on various mainstream sites? Do you notice any pattern to it? Can you access those sites in other browsers on the same system?

I'm no profi, but during the copying of those 100+ crash reports, which for some reason was impossible to do anything other than copy /paste, the designated -bp ones got sent; I discovered from my 2nd notebook as a diagnosis tool which has nearly the identical setup; nearly every crash note of the former one had the comment "throttling" to complete it. Now this is interesting as many of us have slow data links, which creates a deliberate slowdown of data, which providers have to use to avoid too many send/rec errors. Are we trying to chase to much data around for those like myself with slow network speeds, hence the systems get tied up & congested ? Firefox is a data vulture....so I am suggesting for low end performance notebooks, Firefox isn't recommended ? To some extent this is correct as this would be the 2nd Lenov'o notebook that has succumbed to FF techniques ? I've never had this issue with an ACE'R.

The throttling might be on the receiving end. There are a lot of crash reports coming in 24-7, unfortunately.

Modern websites do tend to be very heavy on the bandwidth. You can reduce data usage by using add-ons to reduce third party content that you don't use, such as social sharing buttons, tracking scripts, ads...

I think we are on to something here.....internal architecture of low end PC's that cannot grapple with the FF data hog, get wart'hogged. What I have done on the slow speed system is to rid of unwanted trash...some care is required as there are so many interlocking functions...the Adblock works fine in solitary but with Ghostery (also well treated by Mozilla) beware of unclicking various functions on certain sites that serve two purposes, as to create complex algorithms in notebooks with slow processor architecture. My Leno'vo has fallen to be the victim. It is too slow to be reliable... expect crashes on complex sites. As for hardware acceleration ? FF suggests disable it..but many might notice that the HD is already working overtime to push any poor processor downfalls. My cue is don't necessarily purchase a cheap $200 notebook just because the data speed is lousy and that is crashes....proof is my ACe'r on the other DSL line works fine. Cut down that vulture data !

COREL....

Turned off HD acceleration months ago. Also checked graphic drivers are up to date, which they are. There is the issue of replacing the existing graphics drivers with another animal, but really that shouldn't be necessary.

Still, I narrow my findings to a plug-in error; as detected some flash crashes, even when Adobe & Shockwave flash have been disabled from the FF Add-ons plug in table ? If there is a sneak file that loads regardless, then where is it ?

The adobe flash player 15.7.20033.2203 that comes with Mozilla is corrupt. Several media sites has a version of their own; which auto conflicts with the version installed in Firefox...even though it has been disabled in the add-on manager, FF tries to initiate it.

Mozilla installers install Mozilla programs. Flash was already on your system.

Update your Flash Player Version 18.0.0.203
https://www.adobe.com/products/flashplayer/distribution3.html Note: Windows users must download the “Internet Explorer” and “Plugin-based browsers” installers.

See if there are updates for your graphics drivers https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

richwalters said

The adobe flash player 15.7.20033.2203 that comes with Mozilla is corrupt. Several media sites has a version of their own; which auto conflicts with the version installed in Firefox...even though it has been disabled in the add-on manager, FF tries to initiate it.

That version number sounds like the latest Adobe Acrobat (PDF) plugin, which is installed with Adobe Reader DC and the latest Creative suite. I'm not aware of any version of the Flash player that started with 15.7.

Could you visit my test page here and then copy paste the plugins list back into a reply: https://jeffersonscher.com/res/jstest.php