Serious Problem after adding a new trusted Sub net zone

So this morning I started investigating why our branch office did not respond/ denied all traffic from our main office.

After a while I saw that the default trusted zone was set with a faulty sub net mask.

When I changed the netmask from 255.255.255.0 to 255.255.240.0 people from the branch office started to get infinite pop-ups requesting them to either deny or allow connections from the "new" trusted zone. As paranoid as users can be they started to deny everything and ofcourse that leads to all sorts of failure.

On top of that clients stopped reporting to the remote admin server, ALL clients including those at the main office.

I have very little experience with this software and I'm sure that I have messed something up somewhere but I just can't figure it out.

Main question is, why did all the clients recive all those pop-ups just by adding/changing the trusted zone?

Secondary question is, how do I most effectivly figure out what is failing the clients to report to the remote admin server?

Regards,

Sudour

 

To add some information to this. Firewall filtering setting where automatic or automatic with user exceptions.

Is there any other place where those kind of notifications or pop-ups can trigger?