Most likely this is a port restriction issue - you need ports 80, 443, and 4172 open bidirectionally for clients to connect to View. Also, importantly, port 4172 must be open for BOTH TCP and UDP. If one of those is closed, you get the symptoms descibed. These ports must be open all the way through - you have a lot of firewalls, so you'll need to check them all.
If that's not the case, the next place is to check in the View Administrator - under View Configuration -> Servers, check the connection server settings (click Edit) - for external connections, you need to check the box that says Use PCoIP Secure Gateway for PCoIP Connections to desktop.