Hello. I was having a problem with the copy and paste function in my Firefox browser. I eliminated all other possible problems, and in the end it was Zonealarm that cause this rare issue. I am not sure why Zonealarm causes this issue, but it has been verified by some Firefox members. I have verified it as well. I uninstalled Zonealarm just check if it was causing the issue, and once I uninstalled Zonealarm and and rebooted, the Firefox browser was behaving normally again. I hope the Zonealarm team looks into this problem because I use Firefox all of the time, and the copy and paste function is very valuable to me. Thank you for reading.