Question : Citrix Web Interface error

i have cirix presentation server 4.50
configure with Web Interface https://citrix.domain.com
for client i have native client ( so they have to download the citrix client to get the application)
i have checked my dmz setting the first one correcpond to the itnernal network address, and after that  dafault - translate.
Everyone is able to login with their credential using the WEb interface. However, when they click any applications everyone get the same error above. These server has all the application we need.
how can we make this work out?
Please any advice will be great.
Fausto

Answer : Citrix Web Interface error

yes, that is correct