I face a problem while using forefox browser with a message on screen " Mcafee security HTML Dialog has encountred a problem and needs to close. We are sorry for the inconvenience".
Sometime browser closes automatically and sometime remain in working.
Mcafee automatic updation is also blocked now.
I have checked settings of browser as well as firewall and all are OK with permission to mcafee
[QUOTE=salli]
I face a problem while using forefox browser with a message on screen " Mcafee security HTML Dialog has encountred a problem and needs to close. We are sorry for the inconvenience".
Sometime browser closes automatically and sometime remain in working.
Mcafee automatic updation is also blocked now.
[/QUOTE]
This may be because of the file ‘mghtml.exe’ is damaged/infected with virii. You could try ‘McAfee’s Stinger’ running in safe mode. And see if that detects anything. If it’s not the case of a virus, reinstall your McAfee application, restart, and see if that works ok. 
Also, does this dialog box appear every time you open Mozilla Firefox? Could you try another browser to see if it affects them?
Good luck,
Chris