hello, can you try updating to the latest beta version available and see if you can still reproduce the issue then?: https://www.mozilla.org/firefox/beta/

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select Network. Look for Configure How Firefox Connects and press the Settings button. If you are using a proxy, make sure those settings are correct. If there is no proxy, first use No Proxy. If there is a problem, then try System Proxy.

Some problems occurs when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

I check all that and tried but could not.

Start Firefox in Safe Mode {web Link} by holding down the <Shift>
(Mac Options) key, and then starting Firefox. Is the problem still there?

Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

One more thing that i can not end the task from task manager also.

Do you have the Firefox icon on your quick launch? Right click on it, and select Open New Window. Sometimes this works. If it opens, close it by Menu > File > Exit.

This is not a cure but will make it easier if Firefox locks up in Windows. https://support.mozilla.org/questions/997866 {web link}

When i install it , it run but not load any website.. when i close it and again open message display that your firefox is already running. close firefox or cancel. when i close firefox and again open message display proffile is missing. when i make new profile. again same firefox open but not load any site. when i close and again open it display same message firefox is already running...

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;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select Network. Look for Configure How Firefox Connects and press the Settings button. If you are using a proxy, make sure those settings are correct. If there is no proxy, first use No Proxy. If there is a problem, then try System Proxy.

Some problems occurs when your Internet security program was set to trust the previous version of Firefox, but no longer recognizes your updated version as trusted. Now how to fix the problem: To allow Firefox to connect to the Internet again;

• Make sure your Internet security software is up-to-date (i.e. you are running the latest version).
• Remove Firefox from your program's list of trusted or recognized programs. For detailed instructions, see

Configure firewalls so that Firefox can access the Internet. {web link}

I remove all the Internet security programs and windows firewall is off.

It can not be start in safe mode as by pressing shift key... same problem occurring.

Have you tried running your computer in safe mode?

Right now problem solve by the spyhunter scanner. before that i scan full pc by malware bytes and quickheal also but it couldn't find spyware inside the computer. Let see is it working properly or not for few days...

once again thank you for providing solution..

ohh god again same problem occur... what to do now??

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Start your Computer in safe mode with networking. Then start Firefox. Try Safe web sites. Is the problem still there?

Starting The Computer In Safe Mode;
Free Online Encyclopedia

Run most or all of the listed scanners. Troubleshoot Firefox issues caused by malware article.

I check it in Safe Mode with Networking its run smoothly... when I restart my Computer it run smoothly some times. but when i close firefox and again start it shows same error that firefox is already running. can not end task from the task manager because action is denied. Now what to do??

Can someone explain what is going on with the new 37 version update? https://support.mozilla.org/en-US/questions/1054971

shadyz I've called the big guys to help you at your post. They should respond soon. Good luck.

HirenNiranjani said

I check it in Safe Mode with Networking its run smoothly... when I restart my Computer it run smoothly some times. but

This likely means one of your other programs is causing the issue.

Check the programs that are on your computer

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder. Linux: Check your user manual.

Go thru the list. If you find something that you don't know what it is, use a web search.

Troubleshoot Firefox Issues Caused By Malware {web link}

I just read a post; Firefox 37 has a flaw. Upgrades have been suspended.

Install an older version of Firefox {web link}

FredMcD said

I just read a post; Firefox 37 has a flaw. Upgrades have been suspended. Install an older version of Firefox {web link}

Yeah............ i've been talking about it for quite a while, i don't know why i haven't received any answer at all and isn't this tested more before it's initiated? .....

Fred ,how long do you usually wait to initiate an update on your own firefox?

FredMcD said

I just read a post; Firefox 37 has a flaw. Upgrades have been suspended. Install an older version of Firefox {web link}

Could you show me the post you read? What is the flaw?

Would rolling back to 36.0.4 fix this? I wanted to do that,but i wasn't sure if it could potentially create other issues?