XenApp Server not accepting connections/Unable to launch your application

Error:

Unable to launch your application. Contact your help desk with the following information: Cannot connect to the Citrix XenApp server. The Citrix XenApp server you have selected is not accepting connections.

There are many reasons:

1. Load Evaluator

Check parameters of load evaluators. Check load on server using command Qfarm /load.

2. DNS/host entries on client side

Check DNS/"Host file" on client systems and verify that you are resolving server names successfully on client workstations.

My situation the client is using host name for name resolution. His host file had wrong entries.

3. Check that the application has been published on right server

4. Verify with firewall team that right ports are opened or not. Do telnet from client work station on 1494 or 2598, 80,443 ports

Ex: telnet serverName 1494
      telnet SerevrIP 1494

if it is successful, you should see ICA

5. Check these articles:

http://support.citrix.com/article/CTX128254

http://support.citrix.com/article/CTX128115

Have a nice day!