HDX applications fail to launch and error out with an error message “Engine was not loaded, There is no Citrix SSL Server configured on the specified address. Error Number 183”. 



From the Client side trace we see that the client is unable to make TCP connection with the Second AG Vserver on custom port 8081.
Use the below two Network Connectivity check command to verify the connectivity.
1. CURL
2. nmap

1. The output of CURL Network command gives us the following error message :

Curl utility timing out to make a connection with https://example.com:8081 as per below result.
$ curl --sslv3 -v  -I https://example.com:8081
* Rebuilt URL to: https://example.com:8081/
*   Trying to connect to IP...
* connect to IP port 8081 failed: Operation timed out
* Failed to connect to example.com port 8081: Operation timed out
* Closing connection 0
curl: (7) Failed to connect to host.domain.com port 8081: Operation timed out

2. ​And the output of nmap gives the following output.

nmap command doesn’t shows that example.com server is listening on port 8081.
$ nmap example.com
Starting Nmap at 2017-10-04 20:33 UTC
Nmap scan report for example.com 
Host is up (0.0012s latency).
Not shown: 996 filtered ports
PORT     STATE  SERVICE
80/tcp   open   http
113/tcp  closed ident
8008/tcp open   http
8010/tcp open   xmpp

Nmap done: 1 IP address (1 host up) scanned in 46.81 seconds


 

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Port 8081 was blocked on the Firewall. 
As soon as port 8081 was opened on the Firewall, user was able to launch the HDX apps.

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Problem Cause

Custom port blocked on the External Firewall.