can you try in windows safe mode.

• http://windows.microsoft.com/en-us/windows7/start-your-computer-in-safe-mode

I've been having this problem since v22 and all I've so far seen are nonsense suggestions about a connection with Zonealarm. I use copy and paste so much that I'm forced to revert to v21 or use alternative browsers.

Try to set the Boolean pref dom.event.clipboardevents.enabled to false on the about:config page.

Dear @cor-el, I did this and the problem is still there.

Aren't the keyboard shortcuts not working as well?

• Copy: Ctrl+C or Ctrl+Insert (Mac: Command + C)
• Paste: Ctrl+V or Shift+Insert (Mac: Command + V)
• Cut: Ctrl+X or Shift+Delete (Mac: Command + X)

Dear @cor-el, copy/paste functions works well for me in other apps except Firefox. I tried to boot in safe mode with networking as @Waka_Flocka_Flame told, and the problem is gone just in safe mode!

I have same that , I did this and the problem is still there.Help me ! Thanks ! sua may tinh tai nha Sua may tinh tai nha

Hi ehsan453,

If it works when you boot Windows in Safe Mode then it is likely that your security software is causing this problem.

Other programs apart form ZoneAlarm can cause such issues as well.

Which security software (firewall, anti-virus) do you have?

Dear @cor-el, I just have built-in Windows 8 security software (Windows Defender and Windows Firewall).

You can use the MSConfig program or the Autoruns utility to see which software and services are getting started, but be careful with disabling services.

• http://technet.microsoft.com/en-us/sysinternals/bb963902.aspx

Do a malware check with some malware scanning programs on the Windows computer.
Please scan with all programs because each program detects different malware.

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
• SuperAntispyware:
  http://www.superantispyware.com/
• Microsoft Safety Scanner:
  http://www.microsoft.com/security/scanner/en-us/default.aspx
• Windows Defender: Home Page:
  http://www.microsoft.com/windows/products/winfamily/defender/default.mspx
• Spybot Search & Destroy:
  http://www.safer-networking.org/en/index.html
• AdwCleaner:
  http://www.bleepingcomputer.com/download/adwcleaner/
  http://www.softpedia.com/get/Antivirus/Removal-Tools/AdwCleaner.shtml
• 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

Dear cor-el,

Tnx for your reply. But how can i diagnose which software or services that are getting started, causes this problem?

I tried to disable startup programs one by one from task manager. I noticed a program named QTranslate which translates text from webpages to other languages causes my problem. After I upgraded QTranlate to final version, my problem was gone and Now, copy/paste functions works perfect as well as before! :)

I think new versions of Firefox (v23&24) is not adaptive with previous version of QTranslate. Therefore, after upgrading my Firefox from v22 to v23, my problem occurred and upgrading QTranslate fixed my problem!

hmmm... Just updated to V23 and found - in the about:config - the value noscript.allowClipboard set to false. Toggled it to true and, as of right now, copy and paste seems to be working again...

Dear HarryStottle,

There isn't any preference named "noscript.allowClipboard" in the about:config list!

That is a pref that is added by the NoScript extension. So you won't have it when this extension isn't installed.

cor-el's fix worked for me. I am running Firefox Beta 24.0.

"Set the Boolean pref (true/false) dom.event.clipboardevents.enabled to false on the about:config page."

I would just add these step-by-step instructions.

1. Type about:config in the address bar and press enter. You'll see a long page of configuration settings come up.
2. Search for the line that says dom.event.clipboardevents.enabled
3. Right click on the line and click toggle from the menu to switch the selection from true to false.
4. Close the window X

And you are done. You should now be able to copy and paste text once again. Thanks cor-el for helping me fix this problem. It was driving me crazy.

The thread Owner's problem has been solved. Moderator is locking this thread - off-topic (Firefox Beta posting).