There is a issue with the Citrix Client on Linux with some certificates providers. If the client doesn’t recognize the certificate, you get this error when you try to launch an app:

“You have chosen not to trust the “CA PROVIDER” the issuer of the server security certificate”

and then the app won’t start. It’s likely because the CA hierarchy is not correct. The solution to go round this issue is to place the the missing bits (the CROSS certificate and the SSL ICA certificate) under the certificate folder of the client situated here:

/usr/lib/ICAClient/keystore/cacerts

Now it should be all sorted!