When Zone Alarm does this to me I've been able to fix it, by removing the program (right click) from Zone Alarm's program window.

Then when Zone Alarm asks again for access permission I check the box that says remember my preference then I click yes to Internet permission and do the same for the Server permission request that follows.

Sometimes when programs accessing the internet are changed or server permission is de-activated, Zone Alarm blocks it without warnings.

Once in a while check your Zone Alarm program window to make sure programs that need to act as servers have that function activated.