Today I installed the free Zonealarm firewall version 15.4 . Right away Firefox (version 66.0.2 64bit) began to lock up when multiple tabs were opened once it started locking up everything else in Windows 10 including the mouse began to lock. I had to restart from the power switch to get it working. I have the newest update on 64 bit Win 10. This is only a problem with Firefox. Chrome has no problem. I'd prefer not to use Chrome. Anybody else have that problem? Is there a cure? I did try to ask the ZOnealarm forum but after entering a lot of information to join I just got a message to try again later. Thanks for any help.